JANUARY 25, 2018

  PROSPECTUS  

BlackRock Municipal Bond Fund, Inc.  |  Class K Shares

^Ø  BlackRock High Yield Municipal Fund

Class K: MKYHX

This Prospectus contains information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference.

The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

Not FDIC Insured • May Lose Value • No Bank Guarantee

Fund Overview	Key facts and details about the Fund, including investment objectives, principal investment strategies, principal risk factors, fee and expense information and historical performance information
	Key Facts About BlackRock High Yield Municipal Fund	3
	Investment Objective	3
	Fees and Expenses of the Fund	3
	Principal Investment Strategies of the Fund	4
	Principal Risks of Investing in the Fund	4
	Performance Information	6
	Investment Manager	7
	Portfolio Managers	7
	Purchase and Sale of Fund Shares	7
	Tax Information	7
	Payments to Broker/Dealers and Other Financial Intermediaries	8
Details About the Fund	How the Fund Invests	9
	Investment Risks	11
Account Information	Information about account services, sales charges and waivers, shareholder transactions, and distributions and other payments
	Details About the Share Class	18
	How to Buy, Sell, Exchange and Transfer Shares	19
	Fund’s Rights	23
	Short-Term Trading Policy	24
Management of the Fund	Information about BlackRock and the Portfolio Managers
	BlackRock	26
	Portfolio Manager Information	27
	Conflicts of Interest	28
	Valuation of Fund Investments	29
	Dividends, Distributions and Taxes	30
Financial Highlights	Financial Performance of the Fund	32
General Information	Shareholder Documents	33
	Certain Fund Policies	33
	Statement of Additional Information	34
Glossary	Glossary of Investment Terms	35

For More Information	Fund and Service Providers	Inside Back Cover
	Additional Information	Back Cover

Fund Overview

Key Facts About BlackRock High Yield Municipal Fund

Investment Objective

The investment objective of BlackRock High Yield Municipal Fund (the “High Yield Fund” or the “Fund”) is to provide shareholders with as high a level of income exempt from Federal income taxes as is consistent with the investment policies of the Fund.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold Class K Shares of the Fund.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)	Class K Shares
Management Fee1		0.47%
Distribution and/or Service (12b-1) Fees		None
Other Expenses2		0.16%
Interest Expense		0.09%
Miscellaneous Other Expenses2		0.07%
Acquired Fund Fees and Expenses		0.01%
Total Annual Fund Operating Expenses		0.64%
Fee Waivers and/or Expense Reimbursements1,3		(0.05)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements1,3		0.59%

¹  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 26, BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through October 31, 2019. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of BlackRock Municipal Bond Fund, Inc. (the “Corporation”) or by a vote of a majority of the outstanding voting securities of the Fund.

²  Miscellaneous Other Expenses are based on estimated amounts for the current year.

³  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 26, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.49% of average daily net assets through October 31, 2019. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year		3 Years		5 Years		10 Years
Class K Shares	$	60	$	200	$	352	$	794

Portfolio Turnover:

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 36% of the average value of its portfolio.

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Principal Investment Strategies of the Fund

Under normal circumstances, the High Yield Fund seeks to achieve its objective by investing at least 80% of its assets in municipal bonds. Municipal bonds include debt obligations issued by or on behalf of a governmental entity or other qualifying issuer that pay interest that is, in the opinion of bond counsel to the issuer, generally excludable from gross income for Federal income tax purposes (except that the interest may be includable in taxable income for purposes of the Federal alternative minimum tax). Municipal bonds may be obligations of a variety of issuers, including governmental entities or other qualifying issuers. Issuers may be states, territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities. Municipal bonds also include short-term tax-exempt obligations like municipal notes and variable rate demand obligations.

The High Yield Fund may invest in municipal bonds rated in any rating category or in unrated municipal bonds. Although the Fund may invest in municipal bonds in any rating category, Fund management presently intends to invest at least 65% of the Fund’s net assets in medium- to low-quality bonds as rated by at least one independent rating agency (BBB or lower by S&P Global Ratings (“S&P”) or Fitch Ratings, Inc. (“Fitch”) or Baa or lower by Moody’s Investors Service, Inc. (“Moody’s”)), or if unrated, judged to be of comparable quality by BlackRock. Obligations rated below BBB or Baa are commonly known as “junk bonds.” It is possible that the Fund could invest up to 100% of its assets in “junk bonds.”

The Fund may also invest up to 10% of its assets in municipal bonds that are distressed securities. Distressed securities are securities that are the subject of bankruptcy proceedings or otherwise in default as to the repayment of principal and/or payment of interest at the time of acquisition or are rated in the lowest rating categories by at least one independent rating agency (CC or lower by S&P or Fitch or Ca or lower by Moody’s), or if unrated, judged to be of comparable quality by BlackRock. The Fund will usually invest in municipal bonds that have a maturity of five years or longer.

Principal Risks of Investing in the Fund

Risk is inherent in all investing. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly from day to day and over time. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of principal risks of investing in the Fund.

∎ Debt Securities Risk — Debt securities, such as bonds, involve interest rate risk, credit risk, extension risk, and prepayment risk, among other things.

∎ Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise.

The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management.

To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities.

These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

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∎ Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make principal and interest payments when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on the issuer’s financial condition and on the terms of the securities.

∎ Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall.

∎ Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields.

∎ Distressed Securities Risk — Distressed securities are speculative and involve substantial risks in addition to the risks of investing in junk bonds. The Fund will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. In addition, distressed securities involve the substantial risk that principal will not be repaid. These securities may present a substantial risk of default or may be in default at the time of investment. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the Fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale.

∎ Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund.

∎ Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.

∎ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund’s investments in illiquid securities may reduce the returns of the Fund because it may be difficult to sell the illiquid securities at an advantageous time or price. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure to liquidity risk. Liquidity risk may be the result of, among other things, the reduced number and capacity of traditional market participants to make a market in fixed-income securities or the lack of an active market. Liquid investments may become illiquid or less liquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid and relatively less liquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. This may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed-income mutual funds may be higher than normal. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.

∎ Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

∎ Municipal Securities Risks — Municipal securities risks include the ability of the issuer to repay the obligation, the relative lack of information about certain issuers of municipal securities, and the possibility of future legislative changes which could affect the market for and value of municipal securities. These risks include:

∎ General Obligation Bonds Risks — Timely payments depend on the issuer’s credit quality, ability to raise tax revenues and ability to maintain an adequate tax base.

∎ Revenue Bonds Risks — These payments depend on the money earned by the particular facility or class of facilities, or the amount of revenues derived from another source.

∎ Private Activity Bonds Risks — Municipalities and other public authorities issue private activity bonds to finance development of industrial facilities for use by a private enterprise. The private enterprise pays the principal and interest on the bond, and the issuer does not pledge its faith, credit and taxing power for repayment.

∎ Moral Obligation Bonds Risks — Moral obligation bonds are generally issued by special purpose public authorities of a state or municipality. If the issuer is unable to meet its obligations, repayment of these bonds becomes a moral commitment, but not a legal obligation, of the state or municipality.

∎ Municipal Notes Risks — Municipal notes are shorter term municipal debt obligations. If there is a shortfall in the anticipated proceeds, the notes may not be fully repaid and a Fund may lose money.

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∎ Municipal Lease Obligations Risks — In a municipal lease obligation, the issuer agrees to make payments when due on the lease obligation. Although the issuer does not pledge its unlimited taxing power for payment of the lease obligation, the lease obligation is secured by the leased property.

∎ Tax-Exempt Status Risk — The Fund and its investment manager will rely on the opinion of issuers’ bond counsel and, in the case of derivative securities, sponsors’ counsel, on the tax-exempt status of interest on municipal bonds and payments under derivative securities. Neither the Fund nor its investment manager will independently review the bases for those tax opinions, which may ultimately be determined to be incorrect and subject the Fund and its shareholders to substantial tax liabilities.

Performance Information

The information shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. Class K Shares do not have a performance history as of the date of this prospectus. As a result, the chart and the table give you a picture of the long-term performance for Institutional Shares of the Fund, which are not offered in this prospectus. The performance of Class K Shares would be substantially similar to Institutional Shares because Class K Shares and Institutional Shares are invested in the same portfolio of securities and performance would differ only to the extent that Institutional Shares and Class K Shares have different expenses. The actual returns of Class K Shares would have been higher than those of Institutional Shares because Class K Shares have lower expenses than Institutional Shares. The table compares the Fund’s performance to that of the S&P^® Municipal Bond Index and the Custom High Yield Index. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. As with all such investments, past performance (before and after taxes) is not an indication of future results. The table includes all applicable fees. If the Fund’s investment manager and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information on the Fund’s performance, including its current net asset value, can be obtained by visiting http://www.blackrock.com or can be obtained by phone at (800) 882-0052.

Institutional Shares

ANNUAL TOTAL RETURNS

BlackRock High Yield Municipal Fund

As of 12/31

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During the ten-year period shown in the bar chart, the highest return for a quarter was 16.53% (quarter ended September 30, 2009) and the lowest return for a quarter was -19.35% (quarter ended December 31, 2008).

As of 12/31/17 Average Annual Total Returns	1 Year			5 Years			10 Years
BlackRock High Yield Municipal Fund — Institutional Shares
Return Before Taxes		9.05	%		4.79	%		5.68	%
Return After Taxes on Distributions		9.04	%		4.78	%		5.67	%
Return After Taxes on Distributions and Sale of Fund Shares		7.03	%		4.69	%		5.50	%
S&P ® Municipal Bond Index (Reflects no deduction for fees, expenses or taxes)		4.95	%		3.07	%		4.42	%
Custom High Yield Index1 (Reflects no deduction for fees, expenses or taxes)		8.90	%		5.17	%		5.77	%

¹  The Custom High Yield Index reflects the returns of the S&P^® Customized High Yield Municipal Bond Index for periods prior to January 1, 2013, and the returns of only those bonds in the S&P^® Customized High Yield Municipal Bond Index that have maturities greater than 5 years for periods subsequent to January 1, 2013.

After-tax returns are calculated using the historical highest individual Federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on the investor’s tax situation and may differ from those shown, and the after-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.

Investment Manager

The Fund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”).

Portfolio Managers

Name	Portfolio Manager of the Fund Since	Title
Walter O’Connor, CFA	2006	Managing Director of BlackRock, Inc.
Theodore R. Jaeckel, CFA	2006	Managing Director of BlackRock, Inc.

Purchase and Sale of Fund Shares

Class K Shares of the Fund are available only to (i) certain employee benefit plans, such as health savings accounts, and certain employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs and SARSEPs) (collectively, “Employer-Sponsored Retirement Plans”), (ii) collective trust funds, investment companies and other pooled investment vehicles, each of which may purchase shares of the Fund through a Financial Intermediary (as defined below) that has entered into an agreement with the Fund’s distributor to purchase such shares, (iii) “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, banks and bank trusts, local, city, and state governmental institutions, corporations and insurance company separate accounts, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Fund’s distributor to purchase such shares, (iv) fee-based advisory platforms of a Financial Intermediary that (a) has specifically acknowledged in a written agreement with the Fund’s distributor and/or its affiliate(s) that the Financial Intermediary shall offer such shares to fee-based advisory clients through an omnibus account held at the Fund or (b) transacts in the Fund’s shares through another intermediary that has executed such an agreement and (v) any other investors who met the eligibility criteria for BlackRock Shares or Class K Shares prior to August 15, 2016 and have continually held Class K Shares of the Fund in the same account since August 15, 2016.

You may purchase or redeem shares of the Fund each day the New York Stock Exchange is open. Purchase orders may also be placed by calling (800) 537-4942, by mail (c/o BlackRock, P.O. Box 9819, Providence, Rhode Island 02940-8019), or online at www.blackrock.com. Institutional Investors are subject to a $5 million minimum initial investment requirement. Other investors, including Employer-Sponsored Retirement Plans, have no minimum initial investment requirement. There is no minimum investment amount for additional purchases.

Tax Information

Different income tax rules apply depending on whether you are invested through a qualified plan exempt from tax under section 401(a) of the Internal Revenue Code of 1986, as amended. If you are invested through such a plan (and Fund shares are not “debt-financed property” to the plan), then the dividends paid by the Fund and the gain realized from a

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redemption or exchange of Fund shares will generally not be subject to Federal income taxes until you withdraw or receive distributions from the plan. If you are not invested through such a plan, then the Fund’s dividends and gain from a redemption or exchange may be subject to Federal income taxes and may be taxed as ordinary income or capital gains, unless you are a tax-exempt investor.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a financial professional or selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. and their respective affiliates) (each a “Financial Intermediary”), the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Class K Shares are only available through a Financial Intermediary if the Financial Intermediary will not receive from Fund assets, or the Fund’s distributor’s or an affiliate’s resources, any commission payments, shareholder servicing fees (including sub-transfer agent and networking fees), or distribution fees (including Rule 12b-1 fees) with respect to assets invested in Class K Shares. Ask your individual financial professional or visit your Financial Intermediary’s website for more information.

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Details About the Funds

Included in this prospectus are sections that tell you about buying and selling shares, management information, shareholder features of BlackRock High Yield Municipal Fund (the “High Yield Fund” or the “Fund”) and your rights as a shareholder.

How the Fund Invests

Investment Objective

The investment objective of the High Yield Fund is to provide shareholders with as high a level of income exempt from Federal income taxes as is consistent with the investment policies of the Fund.

Investment Process

BlackRock Advisors, LLC (“BlackRock”) considers a variety of factors when choosing investments, such as:

∎ Credit Quality of Issuers — based on bond ratings and other factors, including economic and financial conditions.

∎ Yield Analysis — takes into account factors such as the different yields available on different types of obligations and the shape of the yield curve (longer term obligations typically have higher yields).

∎ Maturity Analysis — the weighted average maturity of the portfolio will be maintained within a desirable range as determined from time to time. Factors considered include portfolio activity, maturity of the supply of available bonds and the shape of the yield curve. Maturity of a debt security refers to the date upon which debt securities are due to be repaid, that is, the date when the issuer generally must pay back the face amount of the security.

In choosing investments, Fund management analyzes the credit quality of issuers and considers the yields available on municipal bonds with different maturities. In addition, Fund management considers the availability of features that protect against an early call of a bond by the issuer.

The Fund intends to invest so that no more than 25% of the Fund’s assets are represented by the municipal securities of issuers located in the same state.

Principal Investment Strategies

Under normal circumstances, the High Yield Fund seeks to achieve its objective by investing at least 80% of its assets in municipal bonds. This policy is a fundamental policy of the Fund and may not be changed without approval of a majority of the Fund’s outstanding voting securities, as defined in the Investment Company Act of 1940, as amended (the “Investment Company Act”). Municipal bonds include debt obligations issued by or on behalf of a governmental entity or other qualifying issuer that pay interest that is, in the opinion of bond counsel to the issuer, generally excludable from gross income for Federal income tax purposes (except that the interest may be includable in taxable income for purposes of the Federal alternative minimum tax). Municipal bonds may be obligations of a variety of issuers, including governmental entities or other qualifying issuers. Issuers may be states, territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities. Municipal bonds also include short-term tax-exempt obligations like municipal notes and variable rate demand obligations.

The High Yield Fund may invest in municipal bonds rated in any rating category or in unrated municipal bonds. Fund management chooses municipal bonds that it believes offer a relatively high potential for total return relative to their total risk. Although the Fund may invest in municipal bonds in any rating category, Fund management presently intends to invest at least 65% of the Fund’s net assets in medium- to low-quality bonds as rated by at least one independent rating agency (BBB or lower by S&P Global Ratings (“S&P”) or Fitch Ratings, Inc. (“Fitch”) or Baa or lower by Moody’s Investors Service, Inc. (“Moody’s”), or if unrated, judged to be of comparable quality by BlackRock. Obligations rated below BBB or Baa are commonly known as “junk bonds.” It is possible that the Fund could invest up to 100% of its assets in junk bonds. Fund management reserves the right to invest less than 65% of the Fund’s net assets in municipal bonds rated BBB or Baa or lower if Fund management determines that there is an insufficient supply of such obligations available for investment.

The Fund may also invest up to 10% of its total assets in municipal bonds that are considered distressed securities, which are securities that are the subject of bankruptcy proceedings or otherwise in default as to the repayment of principal and/or payment of interest at the time of acquisition or are rated in the lowest rating categories by at least one independent rating agency (CC or lower by S&P or Fitch or Ca or lower by Moody’s), or if unrated, judged to be of comparable quality by BlackRock. The Fund will usually invest in municipal bonds that have a maturity of five years or longer. Generally, the Fund will invest in distressed securities when Fund management believes they offer significant

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potential for higher returns or can be exchanged for other securities that offer this potential. However, there can be no assurance that the Fund will achieve these returns or that the issuer will make an exchange offer or adopt a plan of reorganization.

ABOUT THE PORTFOLIO MANAGEMENT OF THE HIGH YIELD FUND

The Fund is managed by a team of financial professionals. Theodore R. Jaeckel, CFA and Walter O’Connor, CFA, are the portfolio managers and are jointly and primarily responsible for the day-to-day management of the Fund. Please see “Management of the Funds — Portfolio Manager Information” for additional information about the portfolio management team.

Other Strategies

In addition to the principal strategies discussed above, the Fund may also invest or engage in the following investments/strategies:

∎ Borrowing — The Fund may borrow for temporary or emergency purposes, including to meet redemptions, for the payment of dividends, for share repurchases or for the clearance of transactions, subject to the limits set forth under the Investment Company Act, the rules and regulations thereunder and any applicable exemptive relief.

∎ Derivatives — The Fund is permitted to engage in transactions in certain derivatives, such as financial futures contracts and options thereon, indexed and inverse floating rate obligations and swap agreements, including credit default swap agreements. Derivatives are financial instruments whose value is derived from another security or an index such as the S&P Municipal Bond Index. The Fund may use derivative instruments to hedge its investments or to seek to enhance returns. Derivatives allow the Fund to increase or decrease its risk exposure more quickly and efficiently than other types of instruments. The Fund is not required to use hedging and may choose not to do so.

∎ Illiquid/Restricted Securities — The Fund may invest up to 15% of its net assets in illiquid securities that it cannot sell within seven days at approximately current value. Restricted securities are securities that cannot be offered for public resale unless registered under the applicable securities laws or that have a contractual restriction that prohibits or limits their resale (i.e., Rule 144A securities). They may include private placement securities that have not been registered under the applicable securities laws. Restricted securities may not be listed on an exchange and may have no active trading market and therefore may be considered to be illiquid. Rule 144A securities are restricted securities that can be resold to qualified institutional buyers but not to the general public.

∎ Indexed Securities — The Fund may invest in securities the potential return of which is directly related to changes in an underlying index or interest rate, known as indexed securities. The return on indexed securities will rise when the underlying index rises and fall when the index falls.

∎ Investment Companies — The Fund has the ability to invest in other investment companies, such as exchange-traded funds, unit investment trusts, and open-end and closed-end funds. The Fund may invest in affiliated investment companies, including affiliated money market funds and affiliated exchange-traded funds.

∎ Securities Lending — The Fund may lend securities with a value up to 33 ¹⁄₃% of its total assets to financial institutions that provide cash or securities issued or guaranteed by the U.S. Government as collateral.

∎ Taxable Income — Investments in taxable money market securities as well as some of the derivatives discussed herein may cause the Fund to have taxable investment income. The Fund may also realize capital gains on the sale of its municipal bonds (and other securities it holds). These capital gains will be taxable regardless of whether they are derived from a sale of municipal bonds.

∎ Taxable Money Market Securities — The Fund may invest up to 20% of its assets on a temporary basis in taxable money market securities that have a maturity of one year or less. The Fund may make these investments for liquidity purposes or as a temporary investment pending an investment in municipal bonds.

∎ Temporary Defensive Strategies — As a temporary measure for defensive purposes, the Fund may invest without limitation in taxable money market securities. These investments may prevent the Fund from meeting its investment objective.

∎ Tender Option Bonds and Related Securities — The Fund may leverage its assets through the use of proceeds received through tender option bond transactions. In a tender option bond transaction, the Fund transfers municipal bonds or other municipal securities into a special purpose entity (a “TOB Trust”). A TOB Trust typically issues two classes of beneficial interests: short-term floating rate interests (“TOB Floaters”), which are sold to third party investors, and residual inverse floating rate interests (“TOB Residuals”), which are generally issued to the Fund. The Fund may invest in TOB Residuals and may also invest in TOB Floaters. The Fund will look through to the underlying municipal bond held by a TOB Trust for purposes of the Fund’s 80% policy.

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∎ Variable Rate Demand Obligations — The Fund may invest in variable rate demand obligations, which are floating rate securities that combine an interest in a long term municipal bond with a right to demand payment before maturity from a bank or other financial institution.

∎ When-Issued and Delayed Delivery Securities and Forward Commitments — The purchase or sale of securities on a when-issued basis, on a delayed delivery basis or through a forward commitment involves the purchase or sale of securities by the Fund at an established price with payment and delivery taking place in the future. The Fund enters into these transactions to obtain what is considered an advantageous price to the Fund at the time of entering into the transaction.

Investment Risks

This section contains a discussion of the general risks of investing in the Fund. The “Investment Objectives and Policies” section in the Statement of Additional Information (“SAI”) also includes more information about the Fund, its investments and the related risks. As with any fund, there can be no guarantee that the Fund will meet its investment objective or that the Fund’s performance will be positive for any period of time. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or by any bank or governmental agency.

Principal Risks of Investing in the Fund:

∎ Debt Securities Risk — Debt securities, such as bonds, involve interest rate risk, credit risk, extension risk, and prepayment risk, among other things.

Interest Rate Risk — The market value of bonds and other fixed-income securities changes in response to interest rate changes and other factors. Interest rate risk is the risk that prices of bonds and other fixed-income securities will increase as interest rates fall and decrease as interest rates rise. The Fund may be subject to a greater risk of rising interest rates due to the current period of historically low rates. For example, if interest rates increase by 1%, assuming a current portfolio duration of ten years, and all other factors being equal, the value of the Fund’s investments would be expected to decrease by 10%. The magnitude of these fluctuations in the market price of bonds and other fixed-income securities is generally greater for those securities with longer maturities. Fluctuations in the market price of the Fund’s investments will not affect interest income derived from instruments already owned by the Fund, but will be reflected in the Fund’s net asset value. The Fund may lose money if short-term or long-term interest rates rise sharply in a manner not anticipated by Fund management. To the extent the Fund invests in debt securities that may be prepaid at the option of the obligor (such as mortgage-backed securities), the sensitivity of such securities to changes in interest rates may increase (to the detriment of the Fund) when interest rates rise. Moreover, because rates on certain floating rate debt securities typically reset only periodically, changes in prevailing interest rates (and particularly sudden and significant changes) can be expected to cause some fluctuations in the net asset value of the Fund to the extent that it invests in floating rate debt securities. These basic principles of bond prices also apply to U.S. Government securities. A security backed by the “full faith and credit” of the U.S. Government is guaranteed only as to its stated interest rate and face value at maturity, not its current market price. Just like other fixed-income securities, government-guaranteed securities will fluctuate in value when interest rates change.

Following the financial crisis that began in 2007, the Federal Reserve has attempted to stabilize the economy and support the economic recovery by keeping the federal funds rate (the interest rate at which depository institutions lend reserve balances to other depository institutions overnight) at or near zero percent. In addition, as part of its monetary stimulus program known as quantitative easing, the Federal Reserve has purchased on the open market large quantities of securities issued or guaranteed by the U.S. Government, its agencies or instrumentalities. As the Federal Reserve “tapers” or reduces the amount of securities it purchases pursuant to quantitative easing, and/or if the Federal Reserve raises the federal funds rate, there is a risk that interest rates will rise. A general rise in interest rates has the potential to cause investors to move out of fixed-income securities on a large scale, which may increase redemptions from mutual funds that hold large amounts of fixed-income securities. Heavy redemptions could cause the Fund to sell assets at inopportune times or at a loss or depressed value and could hurt the Fund’s performance.

During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns. Certain countries have recently experienced negative interest rates on certain fixed-income instruments. Very low or negative interest rates may magnify interest rate risk. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from Fund performance to the extent the Fund is exposed to such interest rates.

Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make principal and interest payments when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer. The degree of credit risk depends on the issuer’s financial condition and on the terms of the securities.

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Extension Risk — When interest rates rise, certain obligations will be paid off by the obligor more slowly than anticipated, causing the value of these obligations to fall. Rising interest rates tend to extend the duration of securities, making them more sensitive to changes in interest rates. The value of longer-term securities generally changes more in response to changes in interest rates than shorter-term securities. As a result, in a period of rising interest rates, securities may exhibit additional volatility and may lose value.

Prepayment Risk — When interest rates fall, certain obligations will be paid off by the obligor more quickly than originally anticipated, and the Fund may have to invest the proceeds in securities with lower yields. In periods of falling interest rates, the rate of prepayments tends to increase (as does price fluctuation) as borrowers are motivated to pay off debt and refinance at new lower rates. During such periods, reinvestment of the prepayment proceeds by the management team will generally be at lower rates of return than the return on the assets that were prepaid. Prepayment reduces the yield to maturity and the average life of the security.

∎ Distressed Securities Risk — Distressed securities are speculative and involve substantial risks in addition to the risks of investing in junk bonds. The Fund will generally not receive interest payments on the distressed securities and may incur costs to protect its investment. In addition, distressed securities involve the substantial risk that principal will not be repaid. These securities may present a substantial risk of default or may be in default at the time of investment. The Fund may incur additional expenses to the extent it is required to seek recovery upon a default in the payment of principal of or interest on its portfolio holdings. In any reorganization or liquidation proceeding relating to a portfolio company, the Fund may lose its entire investment or may be required to accept cash or securities with a value less than its original investment. Distressed securities and any securities received in an exchange for such securities may be subject to restrictions on resale.

∎ Junk Bonds Risk — Although junk bonds generally pay higher rates of interest than investment grade bonds, junk bonds are high risk investments that are considered speculative and may cause income and principal losses for the Fund. The major risks of junk bond investments include:

∎ Junk bonds may be issued by less creditworthy issuers. Issuers of junk bonds may have a larger amount of outstanding debt relative to their assets than issuers of investment grade bonds. In the event of an issuer’s bankruptcy, claims of other creditors may have priority over the claims of junk bond holders, leaving few or no assets available to repay junk bond holders.

∎ Prices of junk bonds are subject to extreme price fluctuations. Adverse changes in an issuer’s industry and general economic conditions may have a greater impact on the prices of junk bonds than on other higher rated fixed-income securities.

∎ Issuers of junk bonds may be unable to meet their interest or principal payment obligations because of an economic downturn, specific issuer developments, or the unavailability of additional financing.

∎ Junk bonds frequently have redemption features that permit an issuer to repurchase the security from the Fund before it matures. If the issuer redeems junk bonds, the Fund may have to invest the proceeds in bonds with lower yields and may lose income.

∎ Junk bonds may be less liquid than higher rated fixed-income securities, even under normal economic conditions. There are fewer dealers in the junk bond market, and there may be significant differences in the prices quoted for junk bonds by the dealers. Because they are less liquid, judgment may play a greater role in valuing certain of the Fund’s securities than is the case with securities trading in a more liquid market.

∎ The Fund may incur expenses to the extent necessary to seek recovery upon default or to negotiate new terms with a defaulting issuer.

The credit rating of a high yield security does not necessarily address its market value risk. Ratings and market value may change from time to time, positively or negatively, to reflect new developments regarding the issuer.

∎ Leverage Risk — Some transactions may give rise to a form of economic leverage. These transactions may include, among others, derivatives, and may expose the Fund to greater risk and increase its costs. As an open-end investment company registered with the SEC, the Fund is subject to the federal securities laws, including the Investment Company Act, the rules thereunder, and various SEC and SEC staff interpretive positions. In accordance with these laws, rules and positions, the Fund must “set aside” liquid assets (often referred to as “asset segregation”), or engage in other SEC- or staff-approved measures, to “cover” open positions with respect to certain kinds of instruments. The use of leverage may cause the Fund to liquidate portfolio positions when it may not be advantageous to do so to satisfy its obligations or to meet any required asset segregation requirements. Increases and decreases in the value of the Fund’s portfolio will be magnified when the Fund uses leverage.

∎ Liquidity Risk — Liquidity risk exists when particular investments are difficult to purchase or sell. The Fund’s investments in illiquid securities may reduce the returns of the Fund because it may be difficult to sell the illiquid securities at an advantageous time or price. To the extent that the Fund’s principal investment strategies involve derivatives or securities with substantial market and/or credit risk, the Fund will tend to have the greatest exposure

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to liquidity risk. Liquidity risk may be the result of, among other things, the reduced number and capacity of traditional market participants to make a market in fixed-income securities or the lack of an active market. Liquid investments may become illiquid or less liquid after purchase by the Fund, particularly during periods of market turmoil. Illiquid and relatively less liquid investments may be harder to value, especially in changing markets, and if the Fund is forced to sell these investments to meet redemption requests or for other cash needs, the Fund may suffer a loss. This may be magnified in a rising interest rate environment or other circumstances where investor redemptions from fixed-income mutual funds may be higher than normal. In addition, when there is illiquidity in the market for certain securities, the Fund, due to limitations on illiquid investments, may be subject to purchase and sale restrictions.

∎ Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

∎ Municipal Securities Risks — Municipal securities risks include the ability of the issuer to repay the obligation, the relative lack of information about certain issuers of municipal securities, and the possibility of future legislative changes which could affect the market for and value of municipal securities. These risks include:

General Obligation Bonds Risks — The full faith, credit and taxing power of the municipality that issues a general obligation bond secures payment of interest and repayment of principal. Timely payments depend on the issuer’s credit quality, ability to raise tax revenues and ability to maintain an adequate tax base.

Revenue Bonds Risks — Payments of interest and principal on revenue bonds are made only from the revenues generated by a particular facility, class of facilities or the proceeds of a special tax or other revenue source. These payments depend on the money earned by the particular facility or class of facilities, or the amount of revenues derived from another source.

Private Activity Bonds Risks — Municipalities and other public authorities issue private activity bonds to finance development of industrial facilities for use by a private enterprise. The private enterprise pays the principal and interest on the bond, and the issuer does not pledge its full faith, credit and taxing power for repayment. If the private enterprise defaults on its payments, the Fund may not receive any income or get its money back from the investment.

Moral Obligation Bonds Risks — Moral obligation bonds are generally issued by special purpose public authorities of a state or municipality. If the issuer is unable to meet its obligations, repayment of these bonds becomes a moral commitment, but not a legal obligation, of the state or municipality.

Municipal Notes Risks — Municipal notes are shorter term municipal debt obligations. They may provide interim financing in anticipation of, and are secured by, tax collection, bond sales or revenue receipts. If there is a shortfall in the anticipated proceeds, the notes may not be fully repaid and the Fund may lose money.

Municipal Lease Obligations Risks — In a municipal lease obligation, the issuer agrees to make payments when due on the lease obligation. The issuer will generally appropriate municipal funds for that purpose, but is not obligated to do so. Although the issuer does not pledge its unlimited taxing power for payment of the lease obligation, the lease obligation is secured by the leased property. However, if the issuer does not fulfill its payment obligation it may be difficult to sell the property and the proceeds of a sale may not cover the Fund’s loss.

Tax-Exempt Status Risk — In making investments, the Fund and its investment manager will rely on the opinion of issuers’ bond counsel and, in the case of derivative securities, sponsors’ counsel, on the tax-exempt status of interest on municipal obligations and payments under tax-exempt derivative securities. Neither the Fund nor its investment manager will independently review the bases for those tax opinions. If any of those tax opinions are ultimately determined to be incorrect or if events occur after the security is acquired that impact the security’s tax-exempt status, the Fund and its shareholders could be subject to substantial tax liabilities. The Internal Revenue Service (“IRS”) has generally not ruled on the taxability of the securities. An assertion by the IRS that a portfolio security is not exempt from Federal income tax (contrary to indications from the issuer) could affect the Fund’s and its shareholders’ income tax liability for the current or past years and could create liability for information reporting penalties. In addition, an IRS assertion of taxability may impair the liquidity and the fair market value of the securities.

The Fund may also be subject to certain other risks associated with its investments and investment strategies, including:

∎ Borrowing Risk — Borrowing may exaggerate changes in the net asset value of Fund shares and in the return on the Fund’s portfolio. Borrowing will cost the Fund interest expense and other fees. The costs of borrowing may reduce the Fund’s return. Borrowing may cause the Fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations.

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∎ Derivatives Risk — The Fund’s use of derivatives may increase its costs, reduce the Fund’s returns and/or increase volatility. Derivatives involve significant risks, including:

Volatility Risk — The Fund’s use of derivatives may reduce the Fund’s returns and/or increase volatility. Volatility is defined as the characteristic of a security, an index or a market to fluctuate significantly in price within a short time period. A risk of the Fund’s use of derivatives is that the fluctuations in their values may not correlate with the overall securities markets.

Counterparty Risk — Derivatives are also subject to counterparty risk, which is the risk that the other party in the transaction will not fulfill its contractual obligation.

Market and Liquidity Risk — Some derivatives are more sensitive to interest rate changes and market price fluctuations than other securities. The possible lack of a liquid secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close a derivatives position could expose the Fund to losses and could make derivatives more difficult for the Fund to value accurately. The Fund could also suffer losses related to its derivatives positions as a result of unanticipated market movements, which losses are potentially unlimited. Finally, BlackRock may not be able to predict correctly the direction of securities prices, interest rates and other economic factors, which could cause the Fund’s derivatives positions to lose value.

Valuation Risk — Valuation may be more difficult in times of market turmoil since many investors and market makers may be reluctant to purchase complex instruments or quote prices for them. Derivatives may also expose the Fund to greater risk and increase its costs. Certain transactions in derivatives involve substantial leverage risk and may expose the Fund to potential losses that exceed the amount originally invested by the Fund.

Hedging Risk — When a derivative is used as a hedge against a position that the Fund holds, any loss generated by the derivative generally should be substantially offset by gains on the hedged investment, and vice versa. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains. Hedges are sometimes subject to imperfect matching between the derivative and the underlying security, and there can be no assurance that the Fund’s hedging transactions will be effective. The use of hedging may result in certain adverse tax consequences noted below.

Tax Risk — The federal income tax treatment of a derivative may not be as favorable as a direct investment in an underlying asset and may adversely affect the timing, character and amount of income the Fund realizes from its investments. As a result, a larger portion of the Fund’s distributions may be treated as ordinary income rather than as tax-exempt income or as capital gains. In addition, certain derivatives are subject to mark-to-market or straddle provisions of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”). If such provisions are applicable, there could be an increase (or decrease) in the amount of taxable dividends paid by the Fund. Payments received by the Fund from swap agreements, if any, will generally produce taxable income, while payments made by the Fund on swap agreements will be allocated against both tax-exempt and taxable gross income, decreasing the Fund’s distributable net tax-exempt income. In addition, the tax treatment of certain derivatives, such as swaps, is unsettled and may be subject to future legislation, regulation or administrative pronouncements issued by the IRS.

Regulatory Risk — Derivative contracts, including, without limitation, swaps, currency forwards and non-deliverable forwards, are subject to regulation under the Dodd-Frank Wall Street Reform and Consumer Protection Act (“Dodd-Frank Act”) in the United States and under comparable regimes in Europe, Asia and other non-U.S. jurisdictions. Under the Dodd-Frank Act, certain derivatives are subject to margin requirements and swap dealers are required to collect margin from the Fund with respect to such derivatives. Specifically, regulations are now in effect that require swap dealers to post and collect variation margin (comprised of specified liquid instruments and subject to a required haircut) in connection with trading of over-the-counter (“OTC”) swaps with the Fund. Shares of investment companies (other than certain money market funds) may not be posted as collateral under these regulations. Requirements for posting of initial margin in connection with OTC swaps will be phased-in through 2020. In addition, regulations adopted by prudential regulators that will begin to take effect in 2019 will require certain bank-regulated counterparties and certain of their affiliates to include in certain financial contracts, including many derivatives contracts, terms that delay or restrict the rights of counterparties, such as the Fund, to terminate such contracts, foreclose upon collateral, exercise other default rights or restrict transfers of credit support in the event that the counterparty and/or its affiliates are subject to certain types of resolution or insolvency proceedings. The implementation of these requirements with respect to derivatives, as well as regulations under the Dodd-Frank Act regarding clearing, mandatory trading and margining of other derivatives, may increase the costs and risks to the Fund of trading in these instruments and, as a result, may affect returns to investors in the Fund.

Future regulatory developments may impact the Fund’s ability to invest or remain invested in certain derivatives. Legislation or regulation may also change the way in which the Fund itself is regulated. BlackRock cannot predict the effects of any new governmental regulation that may be implemented on the ability of the Fund to use swaps or any other financial derivative product, and there can be no assurance that any new governmental regulation will not adversely affect the Fund’s ability to achieve its investment objective.

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Risks Specific to Certain Derivatives Used by the Fund

Swaps – Swap agreements are two-party contracts entered into for periods ranging from a few weeks to more than one year. In a standard “swap” transaction, two parties agree to exchange the returns (or differentials in rates of return) earned or realized on particular predetermined investments or instruments, which can be adjusted for an interest factor. Swap agreements involve the risk that the party with whom the Fund has entered into the swap will default on its obligation to pay the Fund and the risk that the Fund will not be able to meet its obligations to pay the other party to the agreement.

Credit Default Swaps – Credit default swaps may have as reference obligations one or more securities that are not currently held by the Fund. The protection “buyer” may be obligated to pay the protection “seller” an up-front payment or a periodic stream of payments over the term of the contract, provided generally that no credit event on a reference obligation has occurred. Credit default swaps involve special risks in addition to those mentioned above because they are difficult to value, are highly susceptible to liquidity and credit risk, and generally pay a return to the party that has paid the premium only in the event of an actual default by the issuer of the underlying obligation (as opposed to a credit downgrade or other indication of financial difficulty).

Indexed and Inverse Securities – Indexed and inverse securities provide a potential return based on a particular index of value or interest rates. The Fund’s return on these securities will be subject to risk with respect to the value of the particular index. These securities are subject to leverage risk and correlation risk. Certain indexed and inverse securities have greater sensitivity to changes in interest rates or index levels than other securities, and the Fund’s investment in such instruments may decline significantly in value if interest rates or index levels move in a way Fund management does not anticipate.

Futures – Futures are standardized, exchange-traded contracts that obligate a purchaser to take delivery, and a seller to make delivery, of a specific amount of an asset at a specified future date at a specified price. The primary risks associated with the use of futures contracts and options are: (a) the imperfect correlation between the change in market value of the instruments held by the Fund and the price of the futures contract or option; (b) the possible lack of a liquid secondary market for a futures contract and the resulting inability to close a futures contract when desired; (c) losses caused by unanticipated market movements, which are potentially unlimited; (d) the investment adviser’s inability to predict correctly the direction of securities prices, interest rates, currency exchange rates and other economic factors; and (e) the possibility that the counterparty will default in the performance of its obligations.

Options – An option is an agreement that, for a premium payment or fee, gives the option holder (the purchaser) the right but not the obligation to buy (a “call option”) or sell (a “put option”) the underlying asset (or settle for cash in an amount based on an underlying asset, rate, or index) at a specified price (the “exercise price”) during a period of time or on a specified date. Investments in options are considered speculative. When the Fund purchases an option, it may lose the total premium paid for it if the price of the underlying security or other assets decreased, remained the same or failed to increase to a level at or beyond the exercise price (in the case of a call option) or increased, remained the same or failed to decrease to a level at or below the exercise price (in the case of a put option). If a put or call option purchased by the Fund were permitted to expire without being sold or exercised, its premium would represent a loss to the Fund. To the extent that the Fund writes or sells an option, if the decline or increase in the underlying asset is significantly below or above the exercise price of the written option, the Fund could experience a substantial loss.

∎ Expense Risk — Fund expenses are subject to a variety of factors, including fluctuations in the Fund’s net assets. Accordingly, actual expenses may be greater or less than those indicated. For example, to the extent that the Fund’s net assets decrease due to market declines or redemptions, the Fund’s expenses will increase as a percentage of Fund net assets. During periods of high market volatility, these increases in the Fund’s expense ratio could be significant.

∎ Investment in Other Investment Companies Risk — As with other investments, investments in other investment companies, including ETFs, are subject to market and selection risk. In addition, if the Fund acquires shares of investment companies, including ones affiliated with the Fund, shareholders bear both their proportionate share of expenses in the Fund (including management and advisory fees) and, indirectly, the expenses of the investment companies (to the extent not offset by BlackRock through waivers to the Fund’s management fees). To the extent the Fund is held by an affiliated fund, the ability of the Fund itself to hold other investment companies may be limited.

∎ Municipal Securities Concentration Risk — From time to time the Fund may invest a substantial amount of its assets in municipal securities whose interest is paid solely from revenues of similar projects. If the Fund concentrates its investments in this manner, it assumes the legal and economic risks relating to such projects and this may have a significant impact on the Fund’s investment performance.

∎ Securities Lending Risk — Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned

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securities. The Fund could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. These events could trigger adverse tax consequences for the Fund.

∎ Taxability Risk — The Fund intends to minimize the payment of taxable income to shareholders by investing in tax-exempt or municipal securities in reliance at the time of purchase on an opinion of bond counsel to the issuer that the interest paid on those securities will be excludable from gross income for Federal income tax purposes. Such securities, however, may be determined to pay, or have paid, taxable income subsequent to the Fund’s acquisition of the securities. In that event, the IRS may demand that the Fund pay Federal income taxes on the affected interest income, and, if the Fund agrees to do so, the Fund’s yield could be adversely affected. In addition, the treatment of dividends previously paid or to be paid by the Fund as “exempt interest dividends” could be adversely affected, subjecting the Fund’s shareholders to increased Federal income tax liabilities. If the interest paid on any tax-exempt or municipal security held by the Fund is subsequently determined to be taxable, the Fund will dispose of that security as soon as reasonably practicable. In addition, future laws, regulations, rulings or court decisions may cause interest on municipal securities to be subject, directly or indirectly, to Federal income taxation or interest on state municipal securities to be subject to state or local income taxation, or the value of state municipal securities to be subject to state or local intangible personal property tax, or may otherwise prevent the Fund from realizing the full current benefit of the tax-exempt status of such securities. Any such change could also affect the market price of such securities, and thus the value of an investment in the Fund.

∎ Tender Option Bonds and Related Securities Risk — The Fund’s participation in tender option bond transactions may reduce the Fund’s returns and/or increase volatility. Investments in tender option bond transactions expose the Fund to counterparty risk and leverage risk. An investment in a tender option bond transaction typically will involve greater risk than an investment in a municipal fixed rate security, including the risk of loss of principal. Distributions on TOB Residuals will bear an inverse relationship to short-term municipal security interest rates. Distributions on TOB Residuals paid to the Fund will be reduced or, in the extreme, eliminated as short-term municipal interest rates rise and will increase when short-term municipal interest rates fall. TOB Residuals generally will underperform the market for fixed rate municipal securities in a rising interest rate environment.

The Fund may invest in TOB Trusts on either a non-recourse or recourse basis. TOB Trusts are typically supported by a liquidity facility provided by a third-party bank or other financial institution (the “Liquidity Provider”) that allows the holders of the TOB Floaters to tender their certificates in exchange for payment of par plus accrued interest on any business day, subject to the non-occurrence of tender option termination events. When the Fund invests in a TOB Trust on a non-recourse basis, and the Liquidity Provider is required to make a payment under the liquidity facility, the Liquidity Provider will typically liquidate all or a portion of the municipal securities held in the TOB Trust and then fund the balance, if any, of the amount owed under the liquidity facility over the liquidation proceeds (the “Liquidation Shortfall”).

If the Fund invests in a TOB Trust on a recourse basis, the Fund will typically enter into a reimbursement agreement with the Liquidity Provider where the Fund is required to reimburse the Liquidity Provider the amount of any Liquidation Shortfall. As a result, if the Fund invests in a TOB Trust on a recourse basis, the Fund will bear the risk of loss with respect to any Liquidation Shortfall.

To the extent that the Fund, rather than a third-party bank or financial institution, sponsors a TOB Trust, certain responsibilities that previously belonged to the sponsor bank will be performed by, or on behalf of, the Fund. The Fund’s additional duties and responsibilities under the new TOB Trust structure may give rise to certain additional risks including compliance, securities law and operational risks.

∎ Valuation Risk — The price the Fund could receive upon the sale of any particular portfolio investment may differ from the Fund’s valuation of the investment, particularly for securities that trade in thin or volatile markets or that are valued using a fair valuation methodology or a price provided by an independent pricing service. As a result, the price received upon the sale of an investment may be less than the value ascribed by the Fund, and the Fund could realize a greater than expected loss or lesser than expected gain upon the sale of the investment. Pricing services that value fixed-income securities generally utilize a range of market-based and security-specific inputs and assumptions, as well as considerations about general market conditions, to establish a price. Pricing services generally value fixed-income securities assuming orderly transactions of an institutional round lot size, but may be held or transactions may be conducted in such securities in smaller, odd lot sizes. Odd lots often trade at lower prices than institutional round lots. The Fund’s ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third-party service providers.

∎ Variable Rate Demand Obligations Risks — Variable rate demand obligations are floating rate securities that combine an interest in a long-term municipal bond with a right to demand payment before maturity from a bank or other financial institution. If the bank or financial institution is unable to pay, the Fund may lose money.

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∎ When-Issued and Delayed Delivery Securities and Forward Commitments Risk — When-issued and delayed delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this occurs, the Fund may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

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Account Information

Details About the Share Class

The Fund currently offers multiple share classes (Class K Shares in this prospectus), each with its own sales charge and expense structure, allowing you to invest in the way that best suits your needs. Each share class represents an ownership interest in the same investment portfolio of the Fund. When you choose your class of shares, you should consider the size of your investment and how long you plan to hold your shares. Only certain investors are eligible to buy Class K Shares. Either your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock, The PNC Financial Services Group, Inc. (“PNC”) and their respective affiliates) (each a “Financial Intermediary”) can help you determine whether you are eligible to buy Class K Shares.

The Fund’s shares are distributed by BlackRock Investments, LLC (the “Distributor”), an affiliate of BlackRock.

The table below summarizes key features of Class K Shares of the Fund.

Class K Shares at a Glance
Availability	Available only to (i) certain employee benefit plans, such as health savings accounts, and certain employer-sponsored retirement plans (not including SEP IRAs, SIMPLE IRAs and SARSEPs) (collectively, “Employer-Sponsored Retirement Plans”), (ii) collective trust funds, investment companies and other pooled investment vehicles, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares, (iii) “Institutional Investors,” which include, but are not limited to, endowments, foundations, family offices, banks and bank trusts, local, city, and state governmental institutions, corporations and insurance company separate accounts, each of which may purchase shares of the Fund through a Financial Intermediary that has entered into an agreement with the Distributor to purchase such shares, (iv) fee-based advisory platforms of a Financial Intermediary that (a) has specifically acknowledged in a written agreement with the Distributor and/or its affiliate(s) that the Financial Intermediary shall offer such shares to fee-based advisory clients through an omnibus account held at the Fund or (b) transacts in the Fund’s shares through another intermediary that has executed such an agreement and (v) any other investors who met the eligibility criteria for BlackRock Shares or Class K Shares prior to August 15, 2016 and have continually held Class K Shares of the Fund in the same account since August 15, 2016.
Minimum Investment	$5 million minimum initial investment for Institutional Investors. There is no minimum initial investment requirement for any Employer-Sponsored Retirement Plans or any other eligible investors other than Institutional Investors. There is no minimum investment amount for additional purchases.
Initial Sales Charge?	No. Entire purchase price is invested in shares of the Fund.
Deferred Sales Charge?	No.
Distribution and Service (12b-1) Fees?	No.
Redemption Fees?	No.

The Fund reserves the right to modify or waive the above-stated policies at any time.

When Class K Shares are purchased through a customer’s account in an Employer-Sponsored Retirement Plan through procedures established by the Employer-Sponsored Retirement Plan, confirmation of share purchases and redemptions will be sent to the Employer-Sponsored Retirement Plan. A customer’s ownership of shares will be recorded by the Employer-Sponsored Retirement Plan and reflected in the account statements provided by the Employer-Sponsored Retirement Plan to its participants.

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If you purchased your shares through an Employer-Sponsored Retirement Plan and you transfer your investment from an Employer-Sponsored Retirement Plan to a type of account, such as an individual retirement account, that is not an eligible Class K Share investor in the Fund, you must liquidate your investment in Class K Shares of the Fund and purchase a share class of the Fund or another fund advised by BlackRock or its affiliates that is available for purchase by that type of account.

For investors not purchasing shares through an Employer-Sponsored Retirement Plan, please see below for information on how to buy, sell, exchange and transfer shares.

How to Buy, Sell, Exchange and Transfer Shares

The chart on the following pages summarizes how to buy, sell, exchange and transfer shares through your Financial Intermediary. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, you may also buy, sell, exchange and transfer shares through BlackRock if your account is held directly with BlackRock. To learn more about buying, selling, exchanging or transferring shares through BlackRock, call (800) 537-4942. Because the selection of a mutual fund involves many considerations, your Financial Intermediary may help you with this decision.

With certain limited exceptions, the Fund is generally available only to investors residing in the United States and may not be distributed by a foreign Financial Intermediary. Under this policy, in order to accept new accounts or additional investments (including by way of exchange from another mutual fund sponsored and advised by BlackRock or its affiliates) into existing accounts, the Fund generally requires that (i) a shareholder that is a natural person be a U.S. citizen or resident alien, in each case residing within the United States or a U.S. territory (including APO/FPO/DPO addresses), and have a valid U.S. taxpayer identification number, and (ii) a Financial Intermediary or a shareholder that is an entity be domiciled in the United States and have a valid U.S. taxpayer identification number or be domiciled in a U.S. territory and have a valid U.S. taxpayer identification number or IRS Form W-8. Any existing account that is updated to reflect a non-U.S. address will also be restricted from making additional investments.

The Fund may reject any purchase order, modify or waive the minimum initial or subsequent investment requirements for any shareholders and suspend and resume the sale of any share class of the Fund at any time for any reason. In addition, the Funds may waive certain requirements regarding the purchase, sale, exchange or transfer of shares described below.

Under certain circumstances, if no activity occurs in an account within a time period specified by state law, a shareholder’s shares in a Fund may be transferred to that state.

How to Buy Shares
	Your Choices	Important Information for You to Know
Initial Purchase	Determine the amount of your investment	There is no minimum initial investment for any Employer-Sponsored Retirement Plans or any other investors other than Institutional Investors. For Institutional Investors, there is a $5 million minimum initial investment for all accounts.
	Have your Financial Intermediary submit your purchase order	The price of your shares is based on the next calculation of the Fund’s net asset value after your order is placed. Any purchase orders placed prior to the close of business on the New York Stock Exchange (the “NYSE”) (generally 4:00 p.m. Eastern time) will be priced at the net asset value determined that day. Certain Financial Intermediaries, however, may require submission of orders prior to that time. Purchase orders placed after that time will be priced at the net asset value determined on the next business day. A broker-dealer or financial institution maintaining the account in which you hold shares may charge a separate account, service or transaction fee on the purchase or sale of Fund shares that would be in addition to the fees and expenses shown in the Fund’s “Fees and Expenses” table. The Fund may reject any order to buy shares and may suspend the sale of shares at any time. Certain Financial Intermediaries may charge a processing fee to confirm a purchase.
	Or contact BlackRock (for accounts held directly with BlackRock)	For investors not purchasing shares through an Employer-Sponsored Retirement Plan, to purchase shares directly from BlackRock, call (800) 537-4942 and request a new account application.
Add to Your Investment	Purchase additional shares	There is no minimum investment amount for additional purchases.

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How to Buy Shares (continued)
	Your Choices	Important Information for You to Know
Add to Your Investment (continued)	Have your Financial Intermediary submit your purchase order for additional shares	To purchase additional shares, you may contact your Financial Intermediary or Employer-Sponsored Retirement Plan.
	Or contact BlackRock (for accounts held directly with BlackRock)	For investors not purchasing shares through an Employer-Sponsored Retirement Plan: Purchase by Telephone: Call the Fund at (800) 537-4942 and speak with one of our representatives. The Fund has the right to reject any telephone request for any reason. Purchase by Internet: You may purchase your shares, and view activity in your account, by logging onto the BlackRock website at www.blackrock.com. Purchases made on the Internet using the Automated Clearing House (“ACH”) will have a trade date that is the day after the purchase is made. Certain institutional clients’ purchase orders placed by wire prior to the close of business on the NYSE will be priced at the net asset value determined that day. Contact your Financial Intermediary or BlackRock for further information. Limits on amounts that may be purchased via Internet may vary. For additional information call BlackRock at (800) 537-4942. Please read the On-Line Services Disclosure Statement and User Agreement, the Terms and Conditions page and the Consent to Electronic Delivery Agreement (if you consent to electronic delivery), before attempting to transact online. The Fund employs reasonable procedures to confirm that transactions entered over the Internet are genuine. By entering into the User Agreement with the Fund in order to open an account through the website, the shareholder waives any right to reclaim any losses from the Fund or any of its affiliates, incurred through fraudulent activity.
	Acquire additional shares by reinvesting dividends and capital gains	All dividends and capital gains distributions are automatically reinvested without a sales charge. To make any changes to your dividend and/or capital gains distributions options, please call BlackRock at (800) 537-4942 (for investors who are not purchasing shares through an Employer-Sponsored Retirement Plan) or contact your Financial Intermediary.
How to Pay for Shares	Making payment for purchases	If you are purchasing shares through an Employer-Sponsored Retirement Plan, payment for an order must be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary, but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund. If you are not purchasing shares through an Employer-Sponsored Retirement Plan, payment for shares must normally be made in Federal funds or other immediately available funds by the time specified by your Financial Intermediary but in no event later than 4:00 p.m. (Eastern time) on the first business day following the receipt of the order. Payment may also, at the discretion of the Fund, be made in the form of securities that are permissible investments for the respective fund. If payment is not received by this time, the order will be canceled and you and your Financial Intermediary will be responsible for any loss to the Fund.

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How to Sell Shares
	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares	Have your Financial Intermediary submit your sales order	If you purchased shares through an Employer-Sponsored Retirement Plan, you can make redemption requests through your Financial Intermediary in accordance with the procedures applicable to your accounts. These procedures may vary according to the type of account and the Financial Intermediary involved, and customers should consult their Financial Intermediary in this regard. Financial Intermediaries are responsible for transmitting redemption orders and crediting their customers’ accounts with redemption proceeds on a timely basis. Information relating to such redemption services and charges to process a redemption of shares, if any, should be obtained by customers from their Financial Intermediaries. If you did not purchase your shares through an Employer-Sponsored Retirement Plan, you can make redemption requests through your Financial Intermediary. The price of Class K Shares is based on the next calculation of the Fund’s net asset value after your order is placed. For your redemption request to be priced at the net asset value on the day of your request, you must submit your request to your Financial Intermediary prior to that day’s close of business on the NYSE (generally 4:00 p.m. (Eastern time)). Certain Financial Intermediaries, however, may require submission of orders prior to that time. Any redemption request placed after that time will be priced at the net asset value at the close of business on the next business day. Regardless of the method the Fund uses to make payment of your redemption proceeds (check or wire), your redemption proceeds typically will be sent one to two business days after your request is submitted, but in any event, within seven days. Certain Financial Intermediaries may charge a fee to process a redemption of shares. The Fund may reject an order to sell shares under certain circumstances.
	Selling shares held directly with BlackRock	Methods of Redeeming if You Did Not Purchase Your Shares Through an Employer-Sponsored Retirement Plan Redeem by Telephone: You may sell shares held at BlackRock by telephone request. Call (800) 537-4942 for details. The Fund, its administrators and the Distributor will employ reasonable procedures to confirm that instructions communicated by telephone are genuine. The Fund and its service providers will not be liable for any loss, liability, cost or expense for acting upon telephone instructions that are reasonably believed to be genuine in accordance with such procedures. The Fund may refuse a telephone redemption request if it believes it is advisable to do so. During periods of substantial economic or market change, telephone redemptions may be difficult to complete. Please find below alternative redemption methods. Redeem by Internet: You may redeem in your account, by logging onto the BlackRock website at www.blackrock.com. Proceeds from Internet redemptions will be sent via wire to the bank account of record. Redeem in Writing: Redemption requests may be sent in proper form to BlackRock, P.O. Box 9819, Providence, Rhode Island 02940-8019 or for overnight delivery, 4400 Computer Drive, Westborough, Massachusetts 01588. Under certain circumstances, a medallion signature guarantee will be required. Payment of Redemption Proceeds Redemption proceeds may be paid by check or, if the Fund has verified banking information on file, by wire transfer. Payment by Check: BlackRock will normally mail redemption proceeds within three business days following receipt of a properly completed request, but in any event within seven days. Shares can be redeemed by telephone and the proceeds sent by check to the shareholder at the address on record. Shareholders will pay $15 for redemption proceeds sent by check via overnight mail. You are responsible for any additional charges imposed by your bank for this service.

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How to Sell Shares (continued)
	Your Choices	Important Information for You to Know
Full or Partial Redemption of Shares (continued)	Selling shares held directly with BlackRock (continued)	The Fund reserves the right to reinvest any dividend or distribution amounts (e.g., income dividends or capital gains) which you have elected to receive by check should your check be returned as undeliverable or remain uncashed for more than 6 months. No interest will accrue on amounts represented by uncashed checks. Your check will be reinvested in your account at the net asset value next calculated, on the day of the investment. When reinvested, those amounts are subject to the risk of loss like any fund investment. If you elect to receive distributions in cash and a check remains undeliverable or uncashed for more than 6 months, your cash election may also be changed automatically to reinvest and your future dividend and capital gains distributions will be reinvested in the Fund at the net asset value as of the date of payment of the distribution. Payment by Wire Transfer: Payment for redeemed shares for which a redemption order is received before 4:00 p.m. (Eastern time) on a business day is normally made in Federal funds wired to the redeeming shareholder on the next business day, provided that the Fund’s custodian is also open for business. Payment for redemption orders received after 4:00 p.m. (Eastern time) or on a day when the Fund’s custodian is closed is normally wired in Federal funds on the next business day following redemption on which the Fund’s custodian is open for business. The Fund reserves the right to wire redemption proceeds within seven days after receiving a redemption order if, in the judgment of the Fund, an earlier payment could adversely affect the Fund. Shares can be redeemed by Federal wire transfer to a single previously designated bank account. No charge for wiring redemption payments with respect to Class K Shares is imposed by the Fund. You are responsible for any additional charges imposed by your bank for wire transfers. The Fund is not responsible for the efficiency of the Federal wire system or the shareholder’s firm or bank. To change the name of the single, designated bank account to receive wire redemption proceeds, it is necessary to send a written request to the Fund at the address on the back cover of this prospectus. *** If you make a redemption request before the Fund has collected payment for the purchase of shares, the Fund may delay mailing your proceeds. This delay will usually not exceed ten days.
Redemption Proceeds		Under normal circumstances, the Fund expects to meet redemption requests by using cash or cash equivalents in its portfolio or by selling portfolio assets to generate cash. During periods of stressed market conditions, when a significant portion of the Fund’s portfolio may be comprised of less-liquid investments, the Fund may be more likely to limit cash redemptions and may determine to pay redemption proceeds by (i) borrowing under a line of credit it has entered into with a group of lenders, (ii) borrowing from another BlackRock Fund pursuant to an interfund lending program, to the extent permitted by the Fund’s investment policies and restrictions as set forth in the SAI, and/or (iii) transferring portfolio securities in-kind to you. The SAI includes more information about the Fund’s line of credit and interfund lending program, to the extent applicable. If the Fund pays redemption proceeds by transferring portfolio securities in-kind to you, you may pay transaction costs to dispose of the securities, and you may receive less for them than the price at which they were valued for purposes of redemption.

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How to Transfer Your Account
	Your Choices	Important Information for You to Know
Exchange Privilege	Selling shares of one BlackRock Fund to purchase shares of another BlackRock Fund (“exchanging”)	Class K Shares of the Fund are generally exchangeable for shares of the same class of another BlackRock Fund. Investors who currently own Class K Shares of the Fund may make exchanges into Class K Shares of other BlackRock Funds except for investors holding shares through certain client accounts at Financial Intermediaries that are omnibus with the Fund and do not meet applicable minimums. There is no required minimum amount with respect to exchanges of Class K Shares. You may only exchange into Class K Shares of a BlackRock Fund that is open to new investors or in which you have a current account, if the BlackRock Fund is closed to new investors. To exercise the exchange privilege, you may contact your Financial Intermediary. Alternatively, if your account is held directly with BlackRock, you may: (i) call (800) 537-4942 and speak with one of our representatives, (ii) make the exchange via the Internet by accessing your account online at www.blackrock.com, or (iii) send a written request to the Fund at the address on the back cover of this prospectus. Please note, if you indicated on your New Account Application that you did not want the Telephone Exchange Privilege, you will not be able to place exchanges via the telephone until you update this option either in writing or by calling (800) 537-4942. The Fund has the right to reject any telephone request for any reason. Although there is currently no limit on the number of exchanges that you can make, the exchange privilege may be modified or terminated at any time in the future. The Fund may suspend or terminate your exchange privilege at any time for any reason, including if the Fund believes, in its sole discretion, that you are engaging in market timing activities. See “Short Term Trading Policy” below. For Federal income tax purposes a share exchange is a taxable event and a capital gain or loss may be realized. Please consult your tax adviser or other Financial Intermediary before making an exchange request.
Transfer Shares to Another Financial Intermediary	Transfer to a participating Financial Intermediary	You may transfer your Class K Shares of the Fund only to another Financial Intermediary that has entered into an agreement with the Distributor. Certain shareholder services may not be available for the transferred shares. All future trading of these assets must be coordinated by the receiving firm. Please contact your Financial Intermediary to accomplish the transfer of your Class K Shares.
	Transfer to a non-participating Financial Intermediary	You must either: •   Transfer your Class K Shares to an account with the Fund; or •   Sell your Class K Shares. Please contact your Financial Intermediary to accomplish the transfer of your Class K Shares.

Additional Purchase and Redemption Information Applicable to the Fund if You Are Not Purchasing Shares Through an Employer-Sponsored Retirement Plan

If you are not purchasing shares through an Employer-Sponsored Retirement Plan, the Fund may authorize one or more banks, savings and loan associations and other financial institutions (each a “Service Organization”) to accept purchase and redemption orders on its behalf. Such Service Organizations may be authorized to designate other intermediaries to accept purchase and redemption orders on the Fund’s behalf. If you purchase or redeem shares through a Service Organization or its designee, that entity may have its own deadlines for the receipt of the purchase or redemption order that may be earlier than those stated in the prospectus. The Fund will be deemed to have received a purchase or redemption order when a Service Organization or, if applicable, that Service Organization’s authorized designee, accepts the order. These orders will be priced at the Fund’s net asset value per share next calculated after they are so accepted.

Fund’s Rights

The Fund may:

∎ Suspend the right of redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act;

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∎ Postpone the date of payment upon redemption if trading is halted or restricted on the NYSE or under other emergency conditions described in the Investment Company Act or if a redemption request is made before the Fund has collected payment for the purchase of shares;

∎ Redeem shares for property other than cash as may be permitted under the Investment Company Act; and

∎ Redeem shares involuntarily in certain cases, such as when the value of a shareholder account falls below a specified level.

Note on Low Balance Accounts. Because of the high cost of maintaining smaller shareholder accounts, BlackRock has set a minimum balance of $500 in each Fund position you hold within your account (“Fund Minimum”), and may redeem the shares in your account if the net asset value of those shares in your account falls below $500 for any reason, including market fluctuation.

You will be notified that the value of your account is less than the Fund Minimum before the Fund makes any involuntary redemption. This notification will provide you with a 90 calendar day period to make an additional investment in order to bring the value of your account to at least $500 before the Fund makes an involuntary redemption. This involuntary redemption will not charge any deferred sales charge, and may not apply to accounts of certain employer-sponsored retirement plans (not including IRAs), qualified state tuition plan (529 Plan) accounts, and select fee-based programs at your Financial Intermediary.

Short-Term Trading Policy

The Board of Directors (the “Board”) has determined that the interests of long-term shareholders and the Fund’s ability to manage its investments may be adversely affected when shares are repeatedly bought, sold or exchanged in response to short-term market fluctuations — also known as “market timing.” The Fund is not designed for market timing organizations or other entities using programmed or frequent purchases and sales or exchanges. The exchange privilege for Investor Shares and Institutional Shares is not intended as a vehicle for short-term trading. Excessive purchase and sale or exchange activity may interfere with portfolio management, increase expenses and taxes and may have an adverse effect on the performance of the Fund and its returns to shareholders. For example, large flows of cash into and out of the Fund may require the management team to allocate a significant amount of assets to cash or other short-term investments or sell securities, rather than maintaining such assets in securities selected to achieve the Fund’s investment objective. Frequent trading may cause the Fund to sell securities at less favorable prices, and transaction costs, such as brokerage commissions, can reduce the Fund’s performance.

A fund’s investment in non-U.S. securities is subject to the risk that an investor may seek to take advantage of a delay between the change in value of the fund’s portfolio securities and the determination of the fund’s net asset value as a result of different closing times of U.S. and non-U.S. markets by buying or selling fund shares at a price that does not reflect their true value. A similar risk exists for funds that invest in securities of small capitalization companies, securities of issuers located in emerging markets or high yield securities (junk bonds) that are thinly traded and therefore may have actual values that differ from their market prices. This short-term arbitrage activity can reduce the return received by long-term shareholders. The Fund will seek to eliminate these opportunities by using fair value pricing, as described in “Management of the Fund — Valuation of Fund Investments” below.

The Fund discourages market timing and seeks to prevent frequent purchases and sales or exchanges of Fund shares that it determines may be detrimental to the Fund or long-term shareholders. The Board has approved the policies discussed below to seek to deter market timing activity. The Board has not adopted any specific numerical restrictions on purchases, sales and exchanges of Fund shares because certain legitimate strategies will not result in harm to the Fund or its shareholders.

If as a result of its own investigation, information provided by a Financial Intermediary or other third party, or otherwise, the Fund believes, in its sole discretion, that your short-term trading is excessive or that you are engaging in market timing activity, it reserves the right to reject any specific purchase or exchange order. If the Fund rejects your purchase or exchange order, you will not be able to execute that transaction, and the Fund will not be responsible for any losses you therefore may suffer. For transactions placed directly with the Fund, the Fund may consider the trading history of accounts under common ownership or control for the purpose of enforcing these policies. Transactions placed through the same Financial Intermediary on an omnibus basis may be deemed part of a group for the purpose of this policy and may be rejected in whole or in part by the Fund. Certain accounts, such as omnibus accounts and accounts at Financial Intermediaries, however, include multiple investors and such accounts typically provide the Fund with net purchase or redemption and exchange requests on any given day where purchases, redemptions and exchanges of shares are netted against one another and the identity of individual purchasers, redeemers and exchangers whose orders are aggregated may not be known by the Fund. While the Fund monitors for market timing activity, the Fund may be unable to identify such activities because the netting effect in omnibus accounts often makes it more difficult to locate and eliminate market timers from the Fund. The Distributor has entered into agreements with respect to Financial Intermediaries that maintain omnibus accounts with the Transfer Agent pursuant to which such Financial Intermediaries undertake to cooperate with the Distributor in monitoring purchase, exchange and redemption orders by

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their customers in order to detect and prevent short-term or excessive trading in the Fund’s shares through such accounts. Identification of market timers may also be limited by operational systems and technical limitations. In the event that a Financial Intermediary is determined by the Fund to be engaged in market timing or other improper trading activity, the Fund’s Distributor may terminate such Financial Intermediary’s agreement with the Distributor, suspend such Financial Intermediary’s trading privileges or take other appropriate actions.

There is no assurance that the methods described above will prevent market timing or other trading that may be deemed abusive.

The Fund may from time to time use other methods that it believes is appropriate to deter market timing or other trading activity that may be detrimental to the Fund or long-term shareholders.

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Management of the Fund

BlackRock

BlackRock, the Fund’s investment adviser, manages the Fund’s investments and its business operations subject to the oversight of the Board of the Corporation. While BlackRock is ultimately responsible for the management of the Fund, it is able to draw upon the trading, research and expertise of its asset management affiliates for portfolio decisions and management with respect to certain portfolio securities. BlackRock is an indirect, wholly-owned subsidiary of BlackRock, Inc.

BlackRock, a registered investment adviser, was organized in 1994 to perform advisory services for investment companies. BlackRock and its affiliates had approximately $6.288 trillion in investment company and other portfolio assets under management as of December 31, 2017.

The Fund has entered into a management agreement (the “Management Agreement”) with BlackRock. Under the Management Agreement, BlackRock receives for its services to the Fund a fee based on the Fund’s average daily net assets. For the fiscal year ended June 30, 2017, the aggregate management fees, net of any applicable waivers, paid by the Fund to BlackRock as a percentage of the Fund’s average daily net assets were:

High Yield Fund 0.47 %

High Yield Fund Total Annual Management Fee (Before Waivers)

With respect to the High Yield Fund, the annual management fees payable to BlackRock (as a percentage of average daily net assets) are calculated as follows:

Average Daily Net Assets	Rate of Management Fee
Not exceeding $1 billion		0.47	%
In excess of $1 billion but not exceeding $3 billion		0.44	%
In excess of $3 billion but not exceeding $5 billion		0.42	%
In excess of $5 billion but not exceeding $10 billion		0.41	%
In excess of $10 billion		0.40	%

Prior to November 1, 2016, with respect to the High Yield Fund, the annual management fees payable to BlackRock (as a percentage of average daily net assets) were calculated as follows:

Average Daily Net Assets	Rate of Management Fee
First $250 million		0.550	%
$250 million – $500 million		0.525	%
Greater than $500 million		0.500	%

BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through October 31, 2019. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

BlackRock has voluntarily agreed to waive its management fees by the amount of advisory fees the Fund pays to BlackRock indirectly through its investment in affiliated money market funds (the “affiliated money market fund waiver”).

BlackRock has agreed to cap net expenses (excluding (i) interest, taxes, dividends tied to short sales, brokerage commissions, and other expenditures which are capitalized in accordance with generally accepted accounting principles; (ii) expenses incurred directly or indirectly by the Fund as a result of investments in other investment companies and pooled investment vehicles; (iii) other expenses attributable to, and incurred as a result of, the Fund’s investments; and (iv) other extraordinary expenses (including litigation expenses) not incurred in the ordinary course of the Fund’s business, if any) of Class K shares of the Fund at the levels shown below and in the case of contractual caps, in the Fund’s fees and expenses table in the “Fund Overview” section of this prospectus. Items (i), (ii), (iii) and

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(iv) in the preceding sentence are referred to in this prospectus as “Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses.” To achieve these expense caps, BlackRock has agreed to waive and/or reimburse fees or expenses if these operating expenses exceed a certain limit.

With respect to the Fund, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses to the amounts noted in the table below.

	Contractual Cap1 on Total Annual Fund Operating Expenses2 (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses)
High Yield Fund
Class K Shares		0.49	%
1  The contractual caps for the Fund is in effect through October 31, 2019. The contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund. 2  As a percentage of average daily net assets.

The amount of the contractual waivers and/or reimbursements of fees and expenses made pursuant to the contractual cap on net expenses will be reduced by the amount of the affiliated money market fund waiver.

As stated above, the waivers and reimbursements made pursuant to the contractual expense caps and described in the table above do not include Interest Expense. The Fund’s Interest Expense is required to be reported as part of operating expenses in the Fund’s expense table for accounting purposes. The Fund incurs Interest Expense when making certain investments (e.g., tender option bonds) to seek to enhance the yield and total return of the portfolio. The amount of Interest Expense (if any) will fluctuate with the Fund’s use of those investments.

A discussion of the basis for the Board’s approval of the Management Agreement with BlackRock is included in the Fund’s annual shareholder report for the fiscal year ended June 30, 2017.

From time to time, a manager, analyst, or other employee of BlackRock or its affiliates may express views regarding a particular asset class, company, security, industry, or market sector. The views expressed by any such person are the views of only that individual as of the time expressed and do not necessarily represent the views of BlackRock or any other person within the BlackRock organization. Any such views are subject to change at any time based upon market or other conditions and BlackRock disclaims any responsibility to update such views. These views may not be relied on as investment advice and, because investment decisions for the Fund are based on numerous factors, may not be relied on as an indication of trading intent on behalf of the Fund.

Legal Proceedings. On May 27, 2014, certain purported investors in the BlackRock Global Allocation Fund, Inc. (“Global Allocation”) and the BlackRock Equity Dividend Fund (“Equity Dividend”) filed a consolidated complaint (the “Consolidated Complaint”) in the United States District Court for the District of New Jersey against BlackRock, BlackRock Investment Management, LLC and BlackRock International Limited (collectively, the “Defendants”) under the caption In re BlackRock Mutual Funds Advisory Fee Litigation. The Consolidated Complaint, which purports to be brought derivatively on behalf of Global Allocation and Equity Dividend, alleges that the Defendants violated Section 36(b) of the Investment Company Act by receiving allegedly excessive investment advisory fees from Global Allocation and Equity Dividend. The Consolidated Complaint seeks, among other things, to recover on behalf of Global Allocation and Equity Dividend all allegedly excessive advisory fees received by the Defendants in the period beginning one year prior to the filing of the lawsuit and ending on the date of judgment, along with purported lost investment returns on those amounts, plus interest. The Defendants believe the claims in the Consolidated Complaint are without merit and intend to vigorously defend the action.

Portfolio Manager Information

Information regarding the portfolio managers of the Fund is set forth below. Further information regarding the portfolio managers, including other accounts managed, compensation, ownership of Fund shares, and possible conflicts of interest, is available in the Fund’s SAI.

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The Fund is managed by a team of financial professionals. Walter O’Connor, CFA, and Theodore Jaeckel, CFA, are jointly and primarily responsible for the day-to-day management of the Fund.

Portfolio Manager	Primary Role	Since		Title and Recent Biography
Walter O’Connor, CFA	Responsible for the day-to-day management of each Fund’s portfolio including setting each Fund’s overall investment strategy and overseeing the management of each Fund.		2006	Managing Director of BlackRock, Inc. since 2006.
Theodore R. Jaeckel, CFA	Responsible for the day-to-day management of each Fund’s portfolio including setting each Fund’s overall investment strategy and overseeing the management of each Fund.		2006	Managing Director of BlackRock, Inc. since 2006.

Conflicts of Interest

The investment activities of BlackRock and its affiliates (including BlackRock, Inc. and PNC and their affiliates, directors, partners, trustees, managing members, officers and employees (collectively, the “Affiliates”)) in the management of, or their interest in, their own accounts and other accounts they manage, may present conflicts of interest that could disadvantage the Fund and its shareholders.

BlackRock and its Affiliates provide investment management services to other funds and discretionary managed accounts that follow investment programs similar to that of the Fund. BlackRock and its Affiliates are involved worldwide with a broad spectrum of financial services and asset management activities and may engage in the ordinary course of business in activities in which their interests or the interests of their clients may conflict with those of the Fund. One or more Affiliates act or may act as an investor, investment banker, research provider, investment manager, commodity pool operator, commodity trading advisor, financier, underwriter, adviser, market maker, trader, prime broker, lender, index provider, agent and principal, and have other direct and indirect interests in securities, currencies, commodities, derivatives and other instruments in which the Fund may directly or indirectly invest. Thus, it is likely that the Fund will have multiple business relationships with and will invest in, engage in transactions with, make voting decisions with respect to, or obtain services from, entities for which an Affiliate performs or seeks to perform investment banking or other services. Specifically, the Fund may invest in securities of, or engage in other transactions with, companies with which an Affiliate has developed or is trying to develop investment banking relationships or in which an Affiliate has significant debt or equity investments or other interests. The Fund also may invest in securities of, or engage in other transactions with, companies for which an Affiliate provides or may in the future provide research coverage. An Affiliate may have business relationships with, and purchase, or distribute or sell services or products from or to, distributors, consultants or others who recommend the Fund or who engage in transactions with or for the Fund, and may receive compensation for such services. The Fund may also make brokerage and other payments to Affiliates in connection with the Fund’s portfolio investment transactions. An Affiliate may engage in proprietary trading and advise accounts and funds that have investment objectives similar to those of the Fund and/or that engage in and compete for transactions in the same types of securities, currencies and other instruments as the Fund. This may include transactions in securities issued by other open-end and closed-end investment companies (which may include investment companies that are affiliated with the Fund and BlackRock, to the extent permitted under the Investment Company Act). The trading activities of these Affiliates are carried out without reference to positions held directly or indirectly by the Fund and may result in an Affiliate having positions in certain securities that are senior or junior to, or have interests different from or adverse to, the securities that are owned by the Fund.

No Affiliate is under any obligation to share any investment opportunity, idea or strategy with the Fund. As a result, an Affiliate may compete with the Fund for appropriate investment opportunities. The results of the Fund’s investment activities, therefore, may differ from those of an Affiliate and of other accounts managed by an Affiliate, and it is possible that the Fund could sustain losses during periods in which one or more Affiliates and other accounts achieve profits on their trading for proprietary or other accounts. The opposite result is also possible.

In addition, the Fund may, from time to time, enter into transactions in which an Affiliate or its other clients have an adverse interest. Furthermore, transactions undertaken by Affiliate-advised clients may adversely impact the Fund. Transactions by one or more Affiliate-advised clients or BlackRock may have the effect of diluting or otherwise disadvantaging the values, prices or investment strategies of the Fund. The Fund’s activities may be limited because of regulatory restrictions applicable to one or more Affiliates and/or their internal policies designed to comply with such restrictions.

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Under a securities lending program approved by the Board, the Corporation, on behalf of the Fund, has retained BlackRock Investment Management, LLC (“BIM”), an Affiliate of BlackRock, to serve as the securities lending agent for the Fund to the extent that the Fund participate in the securities lending program. For these services, the lending agent will receive a fee from the Fund, including a fee based on the returns earned on the Fund’s investment of the cash received as collateral for the loaned securities. In addition, one or more Affiliates may be among the entities to which the Fund may lend their portfolio securities under the securities lending program.

The activities of Affiliates may give rise to other conflicts of interest that could disadvantage the Fund and their shareholders. BlackRock has adopted policies and procedures designed to address these potential conflicts of interest. See the SAI for further information.

Valuation of Fund Investments

When you buy shares, you pay the net asset value. This is the offering price. Shares are also redeemed at their net asset value. The Fund calculates the net asset value of each class of its shares each day the NYSE is open, generally as of the close of regular trading hours on the NYSE, based on prices at the time of closing. The NYSE generally closes at 4:00 p.m. (Eastern time). The net asset value used in determining your share price is the next one calculated after your purchase or redemption order is received.

Equity securities and other instruments for which market quotations are readily available are valued at market value, which is generally determined using the last reported closing price or, if a reported closing price is not available, the last traded price on the exchange or market on which the security or instrument is primarily traded at the time of valuation. The Fund values fixed-income portfolio securities and non-exchange traded derivatives using last available bid prices or current market quotations provided by dealers or prices (including evaluated prices) supplied by the Fund’s approved independent third-party pricing services, each in accordance with valuation procedures approved by the Board. Pricing services may use matrix pricing or valuation models that utilize certain inputs and assumptions to derive values. Pricing services generally value fixed-income securities assuming orderly transactions of institutional round lot size, but a Fund may hold or transact in such securities in smaller, odd lot sizes. Odd lots often trade at lower prices than institutional round lots. Short-term debt securities with remaining maturities of 60 days or less may be valued on the basis of amortized cost.

Foreign currency exchange rates are generally determined as of the close of business on the NYSE. Foreign securities owned by the Fund may trade on weekends or other days when the Fund does not price its shares. As a result, the Fund’s net asset value may change on days when you will not be able to purchase or redeem the Fund’s shares.

Generally, trading in foreign securities, U.S. Government securities, money market instruments and certain fixed-income securities is substantially completed each day at various times prior to the close of business on the NYSE. The values of such securities used in computing the net asset value of the Fund’s shares are determined as of such times.

When market quotations are not readily available or are not believed by BlackRock to be reliable, the Fund’s investments are valued at fair value. Fair value determinations are made by BlackRock in accordance with procedures approved by the Board. BlackRock may conclude that a market quotation is not readily available or is unreliable if a security or other asset or liability does not have a price source due to its lack of liquidity, if BlackRock believes a market quotation from a broker-dealer or other source is unreliable, where the security or other asset or other liability is thinly traded (e.g., municipal securities, certain small cap and emerging growth companies, and certain non-U.S. securities) or where there is a significant event subsequent to the most recent market quotation. For this purpose, a “significant event” is deemed to occur if BlackRock determines, in its business judgment prior to or at the time of pricing the Fund’s assets or liabilities, that it is likely that the event will cause a material change to the last closing market price of one or more assets or liabilities held by the Fund. For instance, significant events may occur between the foreign market close and the close of business on the NYSE that may not be reflected in the computation of the Fund’s net assets. If such event occurs, those instruments may be fair valued. Similarly, foreign securities whose values are affected by volatility that occurs in U.S. markets on a trading day after the close of foreign securities markets may be fair valued.

For certain foreign securities, a third-party vendor supplies evaluated, systematic fair value pricing based upon the movement of a proprietary multi-factor model after the relevant foreign markets have closed. This systematic fair value pricing methodology is designed to correlate the prices of foreign securities following the close of the local markets to the price that might have prevailed as of the Fund’s pricing time.

Fair value represents a good faith approximation of the value of a security. The fair value of one or more securities may not, in retrospect, be the price at which those assets could have been sold during the period in which the particular fair values were used in determining the Fund’s net asset value.

The Fund may accept orders from certain authorized Financial Intermediaries or their designees. The Fund will be deemed to receive an order when accepted by the Financial Intermediary or designee, and the order will receive the net asset value next computed by the Fund after such acceptance. If the payment for a purchase order is not made by a designated later time, the order will be canceled and the Financial Intermediary could be held liable for any losses.

29

Dividends, Distributions and Taxes

BUYING A DIVIDEND

Unless your investment is in a tax-deferred account, you may want to avoid buying shares shortly before the Fund pays a dividend, although the impact on you will be significantly less than if you were invested in a fund paying fully taxable dividends. The reason? If you buy shares when the Fund has declared but not yet distributed ordinary income or capital gains, you will pay the full price for the shares and then receive a portion of the price back in the form of a taxable dividend. Before investing you may want to consult your tax adviser.

The Fund will distribute net investment income, if any, monthly and net realized capital gain, if any, at least annually. The Fund may also pay a special distribution at the end of the calendar year to comply with Federal tax requirements. Dividends may be reinvested automatically in shares of the Fund at net asset value or may be taken in cash. If you would like to receive dividends in cash, contact your financial professional, Financial Intermediary or the Fund. Although this cannot be predicted with any certainty, the Fund anticipates that a significant amount of its dividends, if any, will consist of capital gains. Capital gains may be taxable to you at different rates depending on how long the Fund held the assets sold.

The Fund intends to make income distributions, most of which will be excludable from gross income for Federal income tax purposes. Some distributions may be taxable.

The Fund will purchase a municipal security only if it is accompanied by an opinion of counsel to the issuer, which is delivered on the date of issuance of the security, that the interest paid on such security is excludable from gross income for Federal income tax purposes. For purposes of the Fund’s investment strategies, municipal securities and municipal bonds do not include certain tax credit bonds or tax subsidy bonds issued by municipalities and/or states, the interest of which are generally taxable for Federal income tax purposes. Holders of tax credit bonds may be entitled to be allocated income tax credits of certain amounts. To the extent that the dividends distributed by the Fund are derived from bond interest income that is excludable from gross income for Federal income tax purposes, they are exempt from Federal income tax.

There is a possibility that events occurring after the date of issuance of a security, or after the Fund’s acquisition of a security, may result in a determination that the interest on that security is, in fact, includable in gross income for Federal income tax purposes retroactively to its date of issue. Such a determination may cause a portion of prior distributions received by shareholders to be taxable to those shareholders in the year of receipt.

Distributions derived from taxable interest income or capital gains on portfolio securities or derivative instruments, if any, will be subject to Federal income taxes. If you redeem or exchange Fund shares, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Certain investors may be subject to a Federal alternative minimum tax on dividends attributable to a Fund’s investments in private activity bonds.

Generally, within 60 days after the end of the calendar year, the Fund or your Financial Intermediary will tell you the amount of exempt-interest dividends, taxable dividends and capital gain dividends you received that year. Capital gain dividends are taxable as long term capital gains to you, regardless of how long you have held your shares in the Fund. The tax treatment of dividends from the Fund is the same whether you choose to receive them in cash or to have them reinvested in shares of the Fund.

Because of the special tax rules applicable to investments by qualified plans exempt from tax under section 401(a) of the Internal Revenue Code, if you are invested through such a plan, you will not be taxed on dividends paid by the Fund or on the proceeds of a redemption or an exchange of shares of the Fund, provided the shares are not debt-financed property to the plan.

If you are not invested through such a plan, you will generally pay tax on dividends from the Fund whether you receive them in cash or additional shares. In addition, if you redeem Fund shares or exchange them for shares of another fund, you generally will be treated as having sold your shares and any gain on the transaction may be subject to tax. Certain dividend income received by the Fund, including dividends received from U.S. corporations and qualifying foreign corporations, and long-term capital gains, are eligible for taxation at a reduced rate that applies to non-corporate shareholders. In the case of individuals, the reduced tax rate is a maximum rate of 15% for individuals with incomes below approximately $418,000 ($471,000 if married filing jointly), amounts adjusted annually for inflation, and 20% for individuals with any income in excess of those amounts that is long-term capital gain or qualified dividend income. To the extent the Fund makes any distributions derived from long-term capital gains and qualifying dividend income, such distributions will be eligible for taxation at the reduced rates.

A 3.8% Medicare tax is imposed on the net investment income (which includes, but is not limited to, interest, dividends and net gain from investments) of U.S. individuals with income exceeding $200,000, or $250,000 if married filing jointly, and of trusts and estates. However, net investment income does not include distributions from qualified plans exempt from tax under Section 401(a) of the Internal Revenue Code.

30

By law, your dividends and redemption proceeds will be subject to a 28% withholding tax if you have not provided a taxpayer identification number or social security number or the number you have provided is incorrect.

If you are neither a tax resident nor a citizen of the United States or if you are a foreign entity (other than a pass-through entity to the extent owned by U.S. persons), the Fund’s ordinary income dividends (which include distributions of net short-term capital gain) will generally be subject to a 30% U.S. withholding tax, unless a lower treaty rate applies. However, certain distributions reported by the Fund as either interest related dividends or short-term capital gain dividends and paid to a foreign shareholder may be eligible for an exemption from U.S. withholding tax.

A 30% withholding tax is currently imposed on U.S.-source dividends, interest and other income items, and will be imposed on proceeds from the sale of property producing U.S.-source dividends and interest paid after December 31, 2018, to (i) foreign financial institutions, including non-U.S. investment funds, unless they agree to collect and disclose to the IRS information regarding their direct and indirect U.S. account holders and (ii) certain other foreign entities, unless they certify certain information regarding their direct and indirect U.S. owners. To avoid withholding, foreign financial institutions will need to (i) enter into agreements with the IRS that state that they will provide the IRS information, including the names, addresses and taxpayer identification numbers of direct and indirect U.S. accounts and U.S. account holders, comply with due diligence procedures with respect to the identification of U.S. accounts, report to the IRS certain information with respect to U.S. accounts, agree to withhold tax on certain payments made to noncompliant foreign financial institutions or to account holders that fail to provide the required information, and determine certain other information concerning their account holders, or (ii) in the event that an applicable intergovernmental agreement and implementing legislation are adopted, provide local revenue authorities with similar account holder information. Other foreign entities will need to either provide the name, address, and taxpayer identification number of each substantial U.S. owner or certifications of no substantial U.S. ownership unless certain exceptions apply.

Dividends and interest received by the Fund and capital gains recognized by the Fund may give rise to withholding and other taxes imposed by foreign countries. Tax conventions between certain countries and the United States may reduce or eliminate such taxes. You may be able to claim a credit or take a deduction for foreign taxes paid by the Fund if certain requirements are met.

This section summarizes some of the consequences under current Federal tax law of an investment in the Fund. It is not a substitute for individualized tax advice. Consult your tax adviser about the potential tax consequences of an investment in the Fund under all applicable tax laws.

31

Financial Highlights

Since Class K Shares of the Fund have no performance history, the financial information in the table below shows the Fund’s financial performance for the periods indicated for Institutional Shares of the Fund. Although Institutional Shares are not offered in this prospectus, Institutional Shares would have substantially similar performance to the Class K Shares offered in this prospectus because Institutional Shares and Class K Shares are invested in the same portfolio of securities and performance would differ only to the extent that Institutional Shares and Class K Shares do not have the same expenses. The actual returns of Class K Shares would have been higher than those of Institutional Shares because Class K Shares have lower expenses than Institutional Shares. Certain information reflects results for a single Fund share. The total returns in the table represent the rate that an investor would have earned or lost on an investment in the Fund (assuming reinvestment of all dividends and/or distributions). The information has been audited by Deloitte & Touche LLP, whose report, along with the Fund’s audited financial statements, is included in the Fund’s Annual Report, which is available upon request.

Financial Highlights of BlackRock High Yield Municipal Fund

	Institutional
	Year Ended June 30,
	2017			2016			2015			2014			2013
Per Share Operating Performance
Net asset value, beginning of year	$	9.99		$	9.28		$	9.12		$	8.86		$	9.26
Net investment income1		0.41			0.40			0.41			0.44			0.44
Net realized and unrealized gain (loss)		(0.46	)		0.72			0.16			0.26			(0.40	)
Net increase (decrease) from investment operations		(0.05	)		1.12			0.57			0.70			0.04
Distributions from net investment income2		(0.40	)		(0.41	)		(0.41	)		(0.44	)		(0.44	)
Net asset value, end of year	$	9.54		$	9.99		$	9.28		$	9.12		$	8.86
Total Return3
Based on net asset value		(0.38	)%		12.32	%		6.27	%		8.31	%		0.17	%
Ratios to Average Net Assets
Total expenses		0.71	%4		0.71	%4		0.70	%		0.76	%4		0.76	%
Total expenses after fees waived and/or reimbursed and/or paid indirectly		0.66	%4		0.71	%4		0.70	%		0.76	%4		0.76	%
Total expenses after fees waived and/or reimbursed and/or paid indirectly and excluding interest expense and fees5		0.57	%4		0.65	%4		0.66	%		0.69	%4		0.66	%
Net investment income		4.24	%4		4.23	%4		4.37	%		5.02	%4		4.63	%
Supplemental Data
Net assets, end of year (000)	$	516,247		$	554,336		$	327,422		$	242,949		$	198,416
Borrowings outstanding, end of year (000)	$	60,043		$	46,657		$	26,216		$	28,976		$	46,417
Portfolio turnover rate		36	%		19	%		41	%		40	%		21	%

¹  Based on average shares outstanding.

²  Distributions for annual periods determined in accordance with U.S. federal income tax regulations.

³  Where applicable, assumes the reinvestment of distributions.

⁴  Excludes 0.01% of expenses incurred indirectly as a result of investments in underlying funds.

⁵  Interest expense and fees relate to TOB Trusts. See Note 4 of the Notes to Financial Statements for details.

32

General Information

Shareholder Documents

Electronic Access to Annual Reports, Semi-Annual Reports and Prospectuses

Electronic copies of most financial reports and prospectuses are available on BlackRock’s website. Shareholders can sign up for e-mail notifications of annual and semi-annual reports and prospectuses by enrolling in the Fund’s electronic delivery program. To enroll:

Shareholders Who Hold Accounts with Investment Advisers, Banks or Brokerages: Please contact your Financial Intermediary. Please note that not all investment advisers, banks or brokerages may offer this service.

Shareholders Who Hold Accounts Directly With BlackRock:

∎ Access the BlackRock website at http://www.blackrock.com/edelivery; and

∎ Log into your account.

Delivery of Shareholder Documents

The Fund delivers only one copy of shareholder documents, including prospectuses, shareholder reports and proxy statements, to shareholders with multiple accounts at the same address. This practice is known as “householding” and is intended to eliminate duplicate mailings and reduce expenses. Mailings of your shareholder documents may be householded indefinitely unless you instruct us otherwise. If you do not want the mailing of these documents to be combined with those for other members of your household, please contact your Fund at (800) 537-4942.

Certain Fund Policies

Anti-Money Laundering Requirements

The Fund is subject to the USA PATRIOT Act (the “Patriot Act”). The Patriot Act is intended to prevent the use of the U.S. financial system in furtherance of money laundering, terrorism or other illicit activities. Pursuant to requirements under the Patriot Act, the Fund is required to obtain sufficient information from shareholders to enable it to form a reasonable belief that it knows the true identity of its shareholders. This information will be used to verify the identity of investors or, in some cases, the status of Financial Intermediaries. Such information may be verified using third-party sources. This information will be used only for compliance with the Patriot Act or other applicable laws, regulations and rules in connection with money laundering, terrorism, or economic sanctions.

The Fund reserves the right to reject purchase orders from persons who have not submitted information sufficient to allow the Fund to verify their identity. The Fund also reserves the right to redeem any amounts in the Fund from persons whose identity it is unable to verify on a timely basis. It is the Fund’s policy to cooperate fully with appropriate regulators in any investigations conducted with respect to potential money laundering, terrorism, or other illicit activities.

BlackRock Privacy Principles

BlackRock is committed to maintaining the privacy of its current and former fund investors and individual clients (collectively, “Clients”) and to safeguarding their non-public personal information. The following information is provided to help you understand what personal information BlackRock collects, how we protect that information and why in certain cases we share such information with select parties.

If you are located in a jurisdiction where specific laws, rules or regulations require BlackRock to provide you with additional or different privacy-related rights beyond what is set forth below, then BlackRock will comply with those specific laws, rules or regulations.

BlackRock obtains or verifies personal non-public information from and about you from different sources, including the following: (i) information we receive from you or, if applicable, your Financial Intermediary, on applications, forms or other documents; (ii) information about your transactions with us, our affiliates, or others; (iii) information we receive from a consumer reporting agency; and (iv) from visits to our website.

BlackRock does not sell or disclose to non-affiliated third parties any non-public personal information about its Clients, except as permitted by law, or as is necessary to respond to regulatory requests or to service Client accounts. These non-affiliated third parties are required to protect the confidentiality and security of this information and to use it only for its intended purpose.

We may share information with our affiliates to service your account or to provide you with information about other BlackRock products or services that may be of interest to you. In addition, BlackRock restricts access to non-public

33

personal information about its Clients to those BlackRock employees with a legitimate business need for the information. BlackRock maintains physical, electronic and procedural safeguards that are designed to protect the non-public personal information of its Clients, including procedures relating to the proper storage and disposal of such information.

Statement of Additional Information

If you would like further information about the Fund, including how the Fund invests, please see the SAI.

For a discussion of the Fund’s policies and procedures regarding the selective disclosure of its portfolio holdings, please see the SAI. The Fund makes its top ten holdings available on a monthly basis at www.blackrock.com generally within 5 business days after the end of the month to which the information applies.

34

Glossary

This glossary contains an explanation of some of the common terms used in this prospectus. For additional information about the Fund, please see the SAI.

Acquired Fund Fees and Expenses — fees and expenses charged by other investment companies in which a Fund invests a portion of its assets.

Annual Fund Operating Expenses — expenses that cover the costs of operating a Fund.

Custom High Yield Index — a customized benchmark that reflects the returns of the S&P^® Customized High Yield Municipal Bond Index for periods prior to January 1, 2013, and the returns of only those bonds in the S&P^® Customized High Yield Municipal Bond Index that have maturities greater than 5 years for periods subsequent to January 1, 2013.

Distribution Fees — fees used to support a Fund’s marketing and distribution efforts, such as compensating Financial Intermediaries, advertising and promotion.

Management Fee — a fee paid to BlackRock for managing a Fund.

Other Expenses — include accounting, transfer agency, custody, professional fees and registration fees.

Service Fees — fees used to compensate Financial Intermediaries for certain shareholder servicing activities.

Shareholder Fees — these fees include sales charges that you may pay when you buy or sell shares of a Fund.

S&P^® Municipal Bond Index — is composed of bonds held by managed municipal bond fund customers of Standard & Poor’s Securities Pricing, Inc. that are priced daily. Bonds in this Index must have an outstanding par value of at least $2 million and a remaining maturity of not less than one month.

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For More Information

Fund and Service Providers

FUND

BlackRock Municipal Bond Fund, Inc.

BlackRock High Yield Municipal Fund

100 Bellevue Parkway

Wilmington, Delaware 19809

Written Correspondence:

P.O. Box 9819

Providence, Rhode Island 02940-8019

Overnight Mail:

4400 Computer Drive

Westborough, Massachusetts 01588

(800) 537-4942

MANAGER

BlackRock Advisors, LLC

100 Bellevue Parkway

Wilmington, Delaware 19809

TRANSFER AGENT

BNY Mellon Investment Servicing (US) Inc.

301 Bellevue Parkway

Wilmington, Delaware 19809

INDEPENDENT REGISTERED PUBLIC

ACCOUNTING FIRM

Deloitte & Touche LLP

200 Berkeley Street

Boston, Massachusetts 02116

ACCOUNTING SERVICES PROVIDER

State Street Bank and Trust Company

One Lincoln Street

Boston, Massachusetts 02111

DISTRIBUTOR

BlackRock Investments, LLC

40 East 52nd Street

New York, New York 10022

CUSTODIAN

State Street Bank and Trust Company

One Lincoln Street

Boston, Massachusetts 02111

COUNSEL

Willkie Farr & Gallagher LLP

787 Seventh Avenue

New York, New York 10019-6099

Additional Information

For more information:

This prospectus contains important information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference. More information about the Fund is available at no charge upon request. This information includes:

Annual/Semi-Annual Reports

These reports contain additional information about each of the Fund’s investments. The annual report describes the Fund’s performance, lists portfolio holdings, and discusses recent market conditions, economic trends and Fund investment strategies that significantly affected the Fund’s performance for the last fiscal year.

Statement of Additional Information

A Statement of Additional Information (“SAI”) for the Fund, dated January 25, 2018, has been filed with the Securities and Exchange Commission (“SEC”). The SAI, which includes additional information about the Fund, may be obtained free of charge, along with the Fund’s annual and semi-annual reports, by calling (800) 537-4942. The SAI, as supplemented from time to time, is incorporated by reference into this prospectus.

BlackRock Investor Services

Representatives are available to discuss account balance information, mutual fund prospectuses, literature, programs and services available. Hours: 8:00 a.m. to 6:00 p.m. (Eastern time), on any business day. Call: (800) 537-4942

Purchases and Redemptions

Call your Financial Intermediary or BlackRock Investor Services at (800) 537-4942.

World Wide Web

General Fund information and specific Fund performance, including the SAI and annual/semi-annual reports, can be accessed free of charge at www.blackrock.com. Mutual fund prospectuses and literature can also be requested via this website.

Written Correspondence

BlackRock Municipal Bond Fund, Inc.

P.O. Box 9819

Providence, Rhode Island 02940-8019

Overnight Mail

BlackRock Municipal Bond Fund, Inc.

4400 Computer Drive

Westborough, Massachusetts 01588

Internal Wholesalers/Broker Dealer Support

Available on any business day to support investment professionals. Call: (800) 882-0052.

Portfolio Characteristics and Holdings

A description of the Fund’s policies and procedures related to disclosure of portfolio characteristics and holdings is available in the SAI.

For information about portfolio holdings and characteristics, BlackRock fund shareholders and prospective investors may call (800) 882-0052.

Securities and Exchange Commission

You may also view and copy public information about the Fund, including the SAI, by visiting the EDGAR database on the SEC’s website (http://www.sec.gov) or the SEC’s Public Reference Room in Washington, D.C. Copies of this information can be obtained, for a duplicating fee, by electronic request at the following e-mail address: publicinfo@sec.gov, or by writing to the Public Reference Room of the SEC, Washington, D.C. 20549. Information about obtaining documents on the SEC’s website without charge may be obtained by calling (800) SEC-0330.

You should rely only on the information contained in this prospectus. No one is authorized to provide you with information that is different from information contained in this prospectus.

The SEC has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

BLACKROCK MUNICIPAL BOND FUND, INC.

INVESTMENT COMPANY ACT FILE # 811-02688

^© BlackRock Advisors, LLC

PRO-HYM-K-0118

STATEMENT OF ADDITIONAL INFORMATION

BLACKROCK MUNICIPAL BOND FUND, INC.

100 Bellevue Parkway, Wilmington, Delaware 19809 • Phone No. (800) 537-4942

This Statement of Additional Information of the BlackRock High Yield Municipal Fund (the “Fund”), a series of BlackRock Municipal Bond Fund, Inc. (the “Corporation”), is not a prospectus and should be read in conjunction with the Prospectus of the Fund, dated January 25, 2018, as it may be amended or supplemented from time to time (the “Prospectus”) which has been filed with the Securities and Exchange Commission (the “Commission” or the “SEC”) and can be obtained, without charge, by calling (800) 537-4942 or by writing to the Fund at the above address. The Fund’s Prospectus is incorporated by reference into this Statement of Additional Information, and Part I of this Statement of Additional Information and the portions of Part II of this Statement of Additional Information that relate to the Fund have been incorporated by reference into the Fund’s Prospectus. The portions of Part II of this Statement of Additional Information that do not relate to the Fund do not form a part of the Fund’s Statement of Additional Information, have not been incorporated by reference into the Fund’s Prospectus and should not be relied upon by investors in the Fund. The audited financial statements of the Fund are incorporated into this Statement of Additional Information by reference to the Fund’s Annual Report to Shareholders for the fiscal year ended June 30, 2017 (the “Annual Report”). You may request a copy of the Annual Report at no charge by calling (800) 537-4942 between 8:00 a.m. and 6:00 p.m. Eastern time on any business day.

References to the Investment Company Act of 1940, as amended (the “Investment Company Act” or the “1940 Act”), or other applicable law, will include any rules promulgated thereunder and any guidance, interpretations or modifications by the Commission, Commission staff or other authority with appropriate jurisdiction, including court interpretations, and exemptive, no-action or other relief or permission from the Commission, Commission staff or other authority.

Class Ticker	BlackRock High Yield Municipal Fund Ticker Symbol
Class K Shares	MKYHX

BLACKROCK ADVISORS, LLC — MANAGER

BLACKROCK INVESTMENTS, LLC — DISTRIBUTOR

The date of this Statement of Additional Information is January 25, 2018.

TABLE OF CONTENTS

	Page
PART I
Investment Objectives and Policies		I-1
Investment Restrictions		I-6
Information on Directors and Officers		I-8
Management and Advisory Arrangements		I-17
Computation of Offering Price Per Share		I-22
Portfolio Transactions and Brokerage		I-22
Additional Information		I-23
Financial Statements		I-25
PART II
Investment Risks and Considerations		II-1
Management and Other Service Arrangements		II-60
Selective Disclosure of Portfolio Holdings		II-62
Purchase of Shares		II-73
Redemption of Shares		II-87
Shareholder Services		II-89
Pricing of Shares		II-93
Portfolio Transactions and Brokerage		II-96
Dividends and Taxes		II-100
Performance Data		II-107
Proxy Voting Policies and Procedures		II-109
General Information		II-109
Appendix A — Description of Bond Ratings		A-1
Appendix B — Proxy Voting Policies		B-1

PART I: INFORMATION ABOUT BLACKROCK MUNICIPAL BOND FUND, INC.

Part I of this Statement of Additional Information (“SAI”) sets forth information about the BlackRock High Yield Municipal Fund (the “High Yield Fund” or the “Fund”), a series of BlackRock Municipal Bond Fund, Inc. (the “Corporation”). It includes information about the Corporation’s Board of Directors (the “Board” or the “Board of Directors”), the management services provided to and the management fees paid by the Fund and information about other fees applicable to and services provided to the Fund. This Part I of this SAI should be read in conjunction with the Fund’s Prospectus and those portions of Part II of this SAI that pertain to the Fund.

I. Investment Objectives and Policies

In implementing the Fund’s investment strategy, from time to time, BlackRock Advisors, LLC (“BlackRock” or the “Manager”), the Fund’s investment manager, may consider and employ techniques and strategies designed to minimize and defer the U.S. federal income taxes which may be incurred by shareholders in connection with their investment in the Fund.

Set forth below is a listing of some of the types of investments and investment strategies that the Fund may use, and the risks and considerations associated with those investments and investment strategies. Please see Part II of this SAI for further information on these investments and investment strategies. Information contained in Part II about the risks and considerations associated with investments and/or investment strategies applies only to the extent the Fund makes each type of investment or uses each investment strategy. Information that does not apply to the Fund does not form a part of the Fund’s SAI and should not be relied on by investors in the Fund.

	High Yield Fund
144A Securities	X
Asset-Backed Securities
Asset-Based Securities
Precious Metal-Related Securities
Bank Loans
Borrowing and Leverage	X
Cash Flows; Expenses
Cash Management
Collateralized Debt Obligations
Collateralized Bond Obligations
Collateralized Loan Obligations
Commercial Paper
Commodity-Linked Derivative Instruments and Hybrid Instruments
Qualifying Hybrid Instruments
Hybrid Instruments Without Principal Protection
Limitations on Leverage
Counterparty Risk
Convertible Securities
Cyber Security Issues	X
Debt Securities	X
Depositary Receipts (ADRs, EDRs and GDRs)
Derivatives	X
Hedging	X
Indexed and Inverse Securities	X

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	High Yield Fund
Swap Agreements	X
Interest Rate Swaps, Caps and Floors	X
Credit Default Swap Agreements and Similar Instruments	X
Contracts for Difference
Credit Linked Securities	X
Interest Rate Transactions and Swaptions	X
Total Return Swap Agreements	X
Types of Options
Options on Securities and Securities Indices	X
Call Options	X
Put Options	X
Options on Government National Mortgage Association (“GNMA”) Certificates
Risks Associated with Options	X
Futures	X
Risks Associated with Futures	X
Foreign Exchange Transactions
Forward Foreign Exchange Transactions
Currency Futures
Currency Options
Currency Swaps
Limitations on Currency Transactions
Risk Factors in Hedging Foreign Currency
Risk Factors in Derivatives	X
Credit Risk	X
Currency Risk
Leverage Risk	X
Liquidity Risk	X
Correlation Risk	X
Index Risk
Additional Risk Factors of OTC Transactions; Limitations on the Use of OTC Derivatives	X
Distressed Securities	X
Dollar Rolls
Equity Securities
Exchange Traded Notes (“ETNs”)
Foreign Investment Risks
Foreign Market Risk
Foreign Economy Risk
Currency Risk and Exchange Risk
Governmental Supervision and Regulation/Accounting Standards
Certain Risks of Holding Fund Assets Outside the United States
Publicly Available Information
Settlement Risk
Funding Agreements

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	High Yield Fund
Guarantees	X
Illiquid or Restricted Securities	X
Inflation-Indexed Bonds
Inflation Risk	X
Information Concerning the Indexes
Bloomberg Barclays Indices
Interfund Lending Program	X
Borrowing, to the extent permitted by the Fund’s investment policies and restrictions	X
Lending, to the extent permitted by the Fund’s investment policies and restrictions	X
Investment Grade Debt Obligations	X
Investment in Emerging Markets
Brady Bonds
Investment in Other Investment Companies	X
Exchange Traded Funds	X
Junk Bonds	X
Lease Obligations
Liquidity Management	X
Master Limited Partnerships
Mezzanine Investments
Money Market Obligations of Domestic Banks, Foreign Banks and Foreign Branches of U.S. Banks	X
Money Market Securities	X
Mortgage-Related Securities
Mortgage-Backed Securities
Collateralized Mortgage Obligations (“CMOs”)
Adjustable Rate Mortgage Securities
CMO Residuals
Stripped Mortgage-Backed Securities
Tiered Index Bonds
TBA Commitments
Municipal Investments	X
Risk Factors and Special Considerations Relating to Municipal Bonds	X
Description of Municipal Bonds	X
General Obligation Bonds	X
Revenue Bonds	X
Private Activity Bonds (“PABs”)	X
Moral Obligation Bonds	X
Municipal Notes	X
Municipal Commercial Paper	X
Municipal Lease Obligations	X
Tender Option Bonds	X
Yields	X
Variable Rate Demand Obligations (“VRDOs”) and Participating VRDOs	X
Transactions in Financial Futures Contracts	X

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	High Yield Fund
Call Rights	X
Municipal Interest Rate Swap Transactions	X
Insured Municipal Bonds	X
Build America Bonds	X
Participation Notes
Pay-in-kind Bonds	X
Portfolio Turnover Rates	X
Preferred Stock
Real Estate Related Securities
Real Estate Investment Trusts (“REITs”)
Repurchase Agreements and Purchase and Sale Contracts	X
Reverse Repurchase Agreements	X
Rights Offerings and Warrants to Purchase
Securities Lending	X
Short Sales	See note 1 below
Sovereign Debt
Standby Commitment Agreements
Stripped Securities
Structured Notes
Supranational Entities
Tax-Exempt Derivatives	X
Tax-Exempt Preferred Shares	X
Taxability Risk	X
Trust Preferred Securities	X
U.S. Government Obligations	X
U.S. Treasury Obligations	X
Utility Industries	X
When-Issued Securities, Delayed Delivery Securities and Forward Commitments	X
Yields and Ratings	X
Zero Coupon Securities	X

¹  The Fund may only make short sales against-the-box.

The investment objective of the Corporation is to provide shareholders with as high a level of income exempt from Federal income taxes as is consistent with the investment policies of the Fund. The Corporation is classified as a diversified open-end management investment company under the Investment Company Act. The Corporation is comprised of three separate series, each of which is, in effect, a separate fund issuing its own shares. The Fund seeks to achieve its objective by investing in a diversified portfolio of debt obligations issued by or on behalf of states, territories and possessions of the United States and the District of Columbia and their political subdivisions, agencies and instrumentalities, the interest on which, in the opinion of bond counsel to the issuer, is generally excludable from gross income for Federal income tax purposes, except that the interest may be includable in taxable income for purposes of the Federal alternative minimum tax (such obligations are herein referred to as “Municipal Bonds”). Municipal Bonds include general obligation bonds, revenue or special obligation bonds, private activity bonds, variable rate demand notes, and short-term tax-exempt municipal obligations such as tax anticipation notes. Under normal circumstances, the Fund invests at least 80% of its net

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assets in Municipal Bonds. For this purpose, net assets include any borrowings for investment purposes. This is a fundamental policy of the Fund and may not be changed without a vote of the majority of the outstanding shares of the Fund as defined in the Investment Company Act. The Fund may not purchase securities other than Municipal Bonds and certain temporary investments described below. The Fund currently contemplates that it will not invest more than 25% of its total assets (taken at market value) in Municipal Bonds whose issuers are located in the same state. There can be no assurance that the investment objective of the Fund can be attained.

While no Fund intends to realize significant taxable investment income, the Fund has the authority to invest as much as 20% of its assets on a temporary basis in taxable money market securities with remaining maturities not in excess of one year from the date of purchase (“Temporary Investments”) for liquidity purposes or as a temporary investment of cash pending investment of such cash in Municipal Bonds. In addition, the Fund reserves the right to temporarily invest a greater portion of its assets in Temporary Investments for defensive purposes, when, in the judgment of the Manager, market conditions warrant such action. Temporary Investments consist of U.S. Government securities, U.S. Government Agency securities, domestic bank certificates of deposit and bankers’ acceptances, and short-term corporate debt securities such as commercial paper and repurchase agreements. From time to time, the Fund may realize capital gains that will constitute taxable income.

The Fund may invest in certain tax-exempt securities that are classified as “private activity bonds,” which may subject certain investors to an alternative minimum tax.

Certain instruments in which the Fund may invest may be characterized as derivative instruments. The Fund is authorized to engage in transactions in financial futures contracts and options thereon, indexed and inverse floating rate obligations and swap agreements, including credit default swap agreements. The Fund may use derivative instruments to hedge its investments or to seek to enhance returns.

Investment Policies of the Fund

The Fund pursues its investment objective through the separate investment policies described below. These policies differ with respect to the maturity and quality of portfolio securities in which a Fund may invest, and these policies can be expected to affect the yield on the Fund and the degree of market, financial, credit and interest rate risk to which the Fund is subject. Generally, Municipal Bonds with longer maturities tend to produce higher yields and are subject to greater market fluctuations as a result of changes in interest rates (“interest rate risk”) than are Municipal Bonds with shorter maturities. In addition, lower rated Municipal Bonds generally will provide a higher yield than higher rated Municipal Bonds of similar maturity but are also generally subject to greater market risk and to a greater degree of risk with respect to the ability of the issuer to meet its principal and interest obligations (“credit risk”). The Fund’s net asset value may fall when interest rates rise and rise when interest rates fall. Because of its emphasis on investments in Municipal Bonds, the Fund should be considered as a means of diversifying an investment portfolio and not in itself a balanced investment plan.

The High Yield Fund may invest in Municipal Bonds rated in any rating category or in unrated Municipal Bonds. The Fund will usually invest in Municipal Bonds that have a maturity of five years or longer. Fund management chooses Municipal Bonds that it believes offer a relatively high potential for total return relative to their total risk. Although the Fund may invest in Municipal Bonds in any rating category, Fund management presently intends to invest at least 65% of the Fund’s net assets in medium- to low-quality bonds as rated by at least one independent rating agency (BBB or lower by S&P or Fitch or Baa or lower by Moody’s), or if unrated, judged to be of comparable quality by the Fund’s Manager. Obligations rated below BBB or Baa are commonly known as “junk bonds.” It is possible that the Fund could invest up to 100% of its assets in junk bonds. The Fund may also invest up to 10% of its total assets in Municipal Bonds that are the subject of bankruptcy proceedings or otherwise in default as to the repayment of principal and/or payment of interest at the time of acquisition by the Fund or are rated in the lowest rating categories by at least one rating agency (CC or lower by S&P or Fitch or Ca or lower by Moody’s), or if unrated, judged to be of comparable quality by the Fund’s investment adviser.

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Because investment in medium- to lower-rated Municipal Bonds entails relatively greater risks of loss of income or principal than an investment in higher rated securities, an investment in the Fund may not be appropriate for all investors. Investors should consider these risks before investing.

Regulation Regarding Derivatives. The Commodity Futures Trading Commission (“CFTC”) subjects advisers to registered investment companies to regulation by the CFTC if a fund that is advised by the investment adviser either (i) invests, directly or indirectly, more than a prescribed level of its liquidation value in CFTC-regulated futures, options and swaps (“CFTC Derivatives”), or (ii) markets itself as providing investment exposure to such instruments. To the extent the Fund uses CFTC Derivatives, it intends to do so below such prescribed levels and will not market itself as a “commodity pool” or a vehicle for trading such instruments. Accordingly, BlackRock has claimed an exclusion from the definition of the term “commodity pool operator” under the Commodity Exchange Act (“CEA”) pursuant to Rule 4.5 under the CEA. BlackRock is not, therefore, subject to registration or regulation as a “commodity pool operator” under the CEA in respect of the Fund.

Investments in Puerto Rico Municipal Securities. The Fund may invest in municipal securities issued in Puerto Rico, subject to market, economic and political conditions. Like many other U.S. states and municipalities, Puerto Rico experienced a significant downturn during the recent recession. Puerto Rico continues to face significant fiscal challenges, including persistent government deficits, under-funded public pension benefit obligations, underfunded government retirement systems, sizable debt service obligations and a high unemployment rate. Over the last year, Puerto Rico and its authorities have defaulted on various debt payments. On June 30th, President Obama signed the Puerto Rico Oversight, Management and Economic Stability Act (“PROMESA”) into law. PROMESA established a seven-member federal oversight board and a bankruptcy restructuring mechanism for Puerto Rico to adjust its debts in the event voluntary agreements with creditors cannot be reached. On August 31, 2016, President Obama appointed the seven-member board from various lists provided by congressional leadership. The board will assess and certify a fiscal recovery plan and annual budgets presented by the government of Puerto Rico, as well as facilitate debt restructuring talks. A restructuring of some or all of Puerto Rico’s debt, or a further decline in market prices of Puerto Rico debt obligations, may affect a Fund investment in these securities. If the economic situation in Puerto Rico persists or worsens, the volatility, credit quality and performance of the Fund could be adversely affected.

II. Investment Restrictions

The Corporation, on behalf of the Fund, has adopted restrictions and policies relating to the investment of the Fund’s assets and its activities. Certain of the restrictions are fundamental policies of the Corporation and may not be changed without the approval of the holders of a majority of the Corporation’s outstanding voting securities (which for this purpose and under the Investment Company Act, means the lesser of (i) 67% of the shares represented at a meeting at which more than 50% of the outstanding shares are represented or (ii) more than 50% of the outstanding shares). The Corporation, on behalf of the Fund, has also adopted certain non-fundamental investment restrictions, which may be changed by the Board of Directors without shareholder approval.

Set forth below are the Fund’s fundamental and non-fundamental investment restrictions. Unless otherwise provided, all references below to the assets of the Fund are in terms of current market value.

Under the High Yield Fund’s fundamental investment restrictions, the Fund may not:

1. Make any investment inconsistent with the Fund’s classification as a diversified company under the Investment Company Act.

2. Invest more than 25% of its assets, taken at market value, in the securities of issuers in any particular industry (excluding the U.S. Government and its agencies and instrumentalities).

3. Make investments for the purpose of exercising control or management.

4. Purchase or sell real estate, except that, to the extent permitted by applicable law, the Fund may invest in securities directly or indirectly secured by real estate or interests therein or issued by companies which invest in real estate or interests therein.

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5. Make loans to other persons, except (i) that the acquisition of bonds, debentures or other corporate debt securities and investments in government obligations, commercial paper, pass-through instruments, certificates of deposit, bankers’ acceptances, repurchase agreements or any similar instruments shall not be deemed to be the making of a loan, (ii) that the Fund may lend its portfolio securities, provided that the lending of portfolio securities may be made only in accordance with applicable law and the guidelines set forth in the Corporation’s Prospectus and Statement of Additional Information, as they may be amended from time to time and (iii) as may otherwise be permitted by an exemptive order issued to the Fund by the Commission.

6. Issue senior securities to the extent such issuance would violate applicable law.

7. Borrow money, except that (i) the Fund may borrow in amounts up to 33 ¹⁄₃% of its total assets (including the amount borrowed), (ii) the Fund may, to the extent permitted by applicable law, borrow up to an additional 5% of its total assets for temporary purposes, (iii) the Fund may obtain such short term credit as may be necessary for the clearance of purchases and sales of portfolio securities and (iv) the Fund may purchase securities on margin to the extent permitted by applicable law. The Fund may not pledge its assets other than to secure such borrowings or, to the extent permitted by the Fund’s investment policies as set forth in the Corporation’s Prospectus and Statement of Additional Information, as they may be amended from time to time, in connection with hedging transactions, short sales, when-issued and forward commitment transactions and similar investment strategies.

8. Underwrite securities of other issuers except insofar as the Fund technically may be deemed an underwriter under the Securities Act in selling portfolio securities.

9. Purchase or sell commodities or contracts on commodities, except to the extent that the Fund may do so in accordance with applicable law and the Corporation’s Prospectus and Statement of Additional Information, as they may be amended from time to time, and without registering as a commodity pool operator under the Commodity Exchange Act.

Under the High Yield Fund’s non-fundamental investment restrictions, the Fund may not:

a. Purchase securities of other investment companies, except to the extent permitted by the Investment Company Act. As a matter of policy, however, the Fund will not purchase shares of any registered open-end investment company or registered unit investment trust, in reliance on Section 12(d)(1)(F) or (G) (the “fund of funds” provisions) of the Investment Company Act, at any time the Fund has knowledge that its shares are purchased by another investment company investor in reliance on the provisions of subparagraph (G) of Section 12(d)(1).

b. Make short sales of securities or maintain a short position, except to the extent permitted by the Fund’s Prospectus and Statement of Additional Information, as amended from time to time, and applicable law.

Except with respect to restriction (7) of the High Yield Fund, if a percentage restriction on the investment or use of assets set forth above is adhered to at the time a transaction is effected, later changes in percentages resulting from changing values will not be considered a violation.

For purposes of investment restriction (2) of the High Yield Fund above, the Fund uses the classifications and subclassifications of Morgan Stanley Capital International (“MSCI”) as a guide to identify industries. To the extent that an industry classification or subclassification is not provided by MSCI, the Fund may utilize any one or more of the industry classifications or subclassifications used by one or more other widely recognized market indexes or rating group indexes, one or more third party providers of industry classifications, and/or as defined by Fund Management. Currently, for industry classifications or subclassifications not provided by MSCI, the Fund uses the classifications of Interactive Data Corporation. Also for purposes of investment restriction (2), tax-exempt securities issued by states, municipalities and their political subdivisions are not considered to be part of any industry.

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III. Information on Directors and Officers

The Board of Directors of the Corporation consists of eleven individuals (each, a “Director”), nine of whom are not “interested persons” of the Corporation as defined in the Investment Company Act (the “Independent Directors”). The registered investment companies advised by the Manager or its affiliates (the “BlackRock-advised Funds”) are organized into one complex of closed-end funds (the “Closed-End Complex”), two complexes of open-end funds (the “Equity-Liquidity Complex” and the “Equity-Bond Complex”) and one complex of exchange-traded funds (each, a “BlackRock Fund Complex”). Each Fund is included in the BlackRock Fund Complex referred to as the Equity-Bond Complex. The Directors also oversee as board members the operations of the other open-end registered investment companies included in the Equity-Bond Complex.

The Board of Directors has overall responsibility for the oversight of the Corporation and the Funds. The Chair of the Board is an Independent Director, and the Chair of each Board committee (each, a “Committee”) is an Independent Director. The Board has five standing Committees: an Audit Committee, a Governance and Nominating Committee, a Compliance Committee, a Performance Oversight Committee and an Executive Committee. The Chair of the Board’s role is to preside at all meetings of the Board, and to act as a liaison with service providers, officers, attorneys, and other Directors generally between meetings. The Chair of each Committee performs a similar role with respect to the Committee. The Chair of the Board or a Committee may also perform such other functions as may be delegated by the Board or the Committee from time to time. The Independent Directors meet regularly outside the presence of Fund management, in executive session or with other service providers to the Funds. The Board has regular meetings five times a year, and may hold special meetings if required before its next regular meeting. Each Committee meets regularly to conduct the oversight functions delegated to that Committee by the Board and reports its findings to the Board. The Board and each standing Committee conduct annual assessments of their oversight function and structure. The Board has determined that the Board’s leadership structure is appropriate because it allows the Board to exercise independent judgment over management and to allocate areas of responsibility among Committees and the full Board to enhance effective oversight.

The Board has engaged the Manager to manage each Fund on a day-to-day basis. The Board is responsible for overseeing the Manager, other service providers, the operations of each Fund and associated risk in accordance with the provisions of the Investment Company Act, state law, other applicable laws, the Corporation’s charter, and each Fund’s investment objectives and strategies. The Board reviews, on an ongoing basis, each Fund’s performance, operations, and investment strategies and techniques. The Board also conducts reviews of the Manager and its role in running the operations of each Fund.

Day-to-day risk management with respect to each Fund is the responsibility of the Manager or of sub-advisers or other service providers (depending on the nature of the risk), subject to the supervision of the Manager. The Funds are subject to a number of risks, including investment, compliance, operational and valuation risks, among others. While there are a number of risk management functions performed by the Manager and the sub-advisers or other service providers, as applicable, it is not possible to eliminate all of the risks applicable to the Funds. Risk oversight forms part of the Board’s general oversight of each Fund and is addressed as part of various Board and Committee activities. The Board, directly or through a Committee, also reviews reports from, among others, management, the independent registered public accounting firm for each Fund, sub-advisers, and internal auditors for the investment adviser or its affiliates, as appropriate, regarding risks faced by each Fund and management’s or the service provider’s risk functions. The Committee system facilitates the timely and efficient consideration of matters by the Directors, and facilitates effective oversight of compliance with legal and regulatory requirements and of each Fund’s activities and associated risks. The Board has appointed a Chief Compliance Officer, who oversees the implementation and testing of each Fund’s compliance program and reports to the Board regarding compliance matters for the Funds and their service providers. The Independent Directors have engaged independent legal counsel to assist them in performing their oversight responsibilities.

The members of the Audit Committee are Henry R. Keizer (Chair), Bruce R. Bond and Robert M. Hernandez, all of whom are Independent Directors. The principal responsibilities of the Audit Committee are to approve,

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and recommend to the full Board for approval, the selection, retention, termination and compensation of the Corporation’s independent registered public accounting firm (the “Independent Registered Public Accounting Firm”) and to oversee the Independent Registered Public Accounting Firm’s work. The Audit Committee’s responsibilities include, without limitation, to (1) evaluate the qualifications, independence and performance of the Independent Registered Public Accounting Firm; (2) approve all audit engagement terms and fees for the Funds; (3) review the conduct and results of each audit and discuss the Funds’ audited financial statements; (4) review any issues raised by the Independent Registered Public Accounting Firm or Fund management regarding the accounting or financial reporting policies and practices of the Funds and the internal controls of the Funds and certain service providers; (5) oversee the performance of (a) the Funds’ internal audit function provided by its investment adviser and (b) the Independent Registered Public Accounting Firm; (6) oversee policies, procedures and controls regarding valuation of the Funds’ investments and their classification as liquid or illiquid; (7) discuss with Fund management its policies regarding risk assessment and risk management as such matters relate to the Funds’ financial reporting and controls; (8) resolve any disagreements between Fund management and the Independent Registered Public Accounting Firm regarding financial reporting; and (9) undertake such other duties and responsibilities as may from time to time be delegated by the Board to the Audit Committee. The Board has adopted a written charter for the Audit Committee. During the fiscal year ended June 30, 2017, the Audit Committee met four times.

The members of the Governance and Nominating Committee (the “Governance Committee”) are Bruce R. Bond (Chair), Robert M. Hernandez and Henry R. Keizer, all of whom are Independent Directors. The principal responsibilities of the Governance Committee are to (1) identify individuals qualified to serve as Independent Directors of the Corporation and recommend Independent Director nominees for election by shareholders or appointment by the Board; (2) advise the Board with respect to Board composition, procedures and committees (other than the Audit Committee); (3) oversee periodic self-assessments of the Board and committees of the Board (other than the Audit Committee); (4) review and make recommendations regarding Independent Director compensation; (5) monitor corporate governance matters and develop appropriate recommendations to the Board; (6) act as the administrative committee with respect to Board policies and procedures, committee policies and procedures (other than the Audit Committee) and codes of ethics as they relate to Independent Directors; and (7) undertake such other duties and responsibilities as may from time to time be delegated by the Board to the Governance Committee. The Governance Committee may consider nominations for the office of Director made by Fund shareholders as it deems appropriate. Fund shareholders who wish to recommend a nominee should send nominations to the Secretary of the Corporation that include biographical information and set forth the qualifications of the proposed nominee. The Board has adopted a written charter for the Governance Committee. During the fiscal year ended June 30, 2017, the Governance Committee met four times.

The members of the Compliance Committee are Lena G. Goldberg (Chair), James H. Bodurtha and the Honorable Stuart E. Eizenstat, all of whom are Independent Directors. The Compliance Committee’s purpose is to assist the Board in fulfilling its responsibility to oversee regulatory and fiduciary compliance matters involving the Corporation, the fund-related activities of BlackRock and any sub-adviser and the Corporation’s third-party service providers. The Compliance Committee’s responsibilities include, without limitation, to (1) oversee the compliance policies and procedures of the Corporation and its service providers and recommend changes or additions to such policies and procedures; (2) review information on and, where appropriate, recommend policies concerning the Corporation’s compliance with applicable law; (3) review reports from, oversee the annual performance review of, and make certain recommendations and determinations regarding the Corporation’s Chief Compliance Officer (the “CCO”), including determining the amount and structure of the CCO’s compensation and recommending such amount and structure to the full Board for approval and ratification; and (4) undertake such other duties and responsibilities as may from time to time be delegated by the Board to the Compliance Committee. The Board has adopted a written charter for the Compliance Committee. During the fiscal year ended June 30, 2017, the Compliance Committee met four times.

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The members of the Performance Oversight Committee (the “Performance Committee”) are Donald C. Opatrny (Chair), Henry Gabbay and John F. O’Brien, all of whom are Independent Directors, and Robert Fairbairn, who is an interested Director. The Performance Committee’s purpose is to assist the Board in fulfilling its responsibility to oversee the Fund’s investment performance relative to its agreed-upon performance objectives. The Performance Committee’s responsibilities include, without limitation, to (1) review each Fund’s investment objectives, policies and practices; (2) recommend to the Board specific investment tools and techniques employed by BlackRock; (3) recommend to the Board appropriate investment performance objectives based on its review of appropriate benchmarks and competitive universes; (4) review each Fund’s investment performance relative to agreed-upon performance objectives; (5) review information on unusual or exceptional investment matters; and (6) undertake such other duties and responsibilities as may from time to time be delegated by the Board to the Performance Committee. The Board has adopted a written charter for the Performance Committee. During the fiscal year ended June 30, 2017, the Performance Committee met four times.

The members of the Executive Committee are Bruce R. Bond, Lena G. Goldberg, Robert M. Hernandez, Henry R. Keizer and Donald C. Opatrny, all of whom are Independent Directors, and Robert Fairbairn, who serves as an interested Director. The principal responsibilities of the Executive Committee are to (1) act on routine matters between meetings of the Board; (2) act on such matters as may require urgent action between meetings of the Board; and (3) exercise such other authority as may from time to time be delegated to the Executive Committee by the Board. The Board has adopted a written charter for the Executive Committee. During the fiscal year ended June 30, 2017, the Executive Committee did not meet.

The Independent Directors have adopted a statement of policy that describes the experience, qualifications, skills and attributes that are necessary and desirable for potential Independent Director candidates (the “Statement of Policy”). The Board believes that each Independent Director satisfied, at the time he or she was initially elected or appointed a Director, and continues to satisfy, the standards contemplated by the Statement of Policy. Furthermore, in determining that a particular Independent Director was and continues to be qualified to serve as a Director, the Board has considered a variety of criteria, none of which, in isolation, was controlling. The Board believes that, collectively, the Independent Directors have balanced and diverse experience, skills, attributes and qualifications, which allow the Board to operate effectively in governing the Corporation and protecting the interests of shareholders. Among the attributes common to all Independent Directors are their ability to review critically, evaluate, question and discuss information provided to them, to interact effectively with the Funds’ investment adviser, sub-advisers, other service providers, counsel and the Independent Registered Public Accounting Firm, and to exercise effective business judgment in the performance of their duties as Directors.

Each Director’s ability to perform his or her duties effectively is evidenced by his or her educational background or professional training; business, consulting, public service or academic positions; experience from service as a board member of the Corporation and the other funds in the BlackRock Fund Complexes (and any predecessor funds), other investment funds, public companies, non-profit entities or other organizations; ongoing commitment to and participation in Board and Committee meetings, as well as his or her leadership of standing and ad hoc committees throughout the years; or other relevant life experiences.

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The table below discusses some of the experiences, qualifications and skills of each of the Directors that support the conclusion that each board member should serve (or continue to serve) on the Board.

Directors	Experience, Qualifications and Skills
Independent Directors
James H. Bodurtha	James H. Bodurtha has served for more than 25 years on the boards of registered investment companies, most recently as a member of the Board of the Equity-Bond Complex and its predecessor funds, including as Chairman of the Board of certain of the legacy-Merrill Lynch Investment Managers, L.P. (“MLIM”) funds. Prior thereto, Mr. Bodurtha was counsel to and a member of the board of a smaller bank-sponsored mutual funds group. In addition, Mr. Bodurtha is a member of, and previously served as Chairman of, the Independent Directors Council and served for 11 years as an independent director on the Board of Governors of the Investment Company Institute. He also has more than 30 years of executive management and business experience through his work as a consultant and as the chairman of the board of a privately-held company. In addition, Mr. Bodurtha has more than 20 years of legal experience as a corporate attorney and partner in a law firm, where his practice included counseling registered investment companies and their boards.
Bruce R. Bond	Bruce R. Bond has served for approximately 20 years on the board of registered investment companies, having served as a member of the Board of the Equity-Bond Complex and its predecessor funds, including the legacy-BlackRock funds and the State Street Research Mutual Funds. He also has executive management and business experience, having served as president and chief executive officer of several communications networking companies. Mr. Bond also has corporate governance experience from his service as a director of a computer equipment company. Mr. Bond has been determined by the Audit Committee to be an audit committee financial expert, as such term is defined in the applicable SEC rules.
The Honorable Stuart E. Eizenstat	The Honorable Stuart E. Eizenstat has served for approximately 16 years on the board of registered investment companies, having served as a member of the Board of the Equity-Bond Complex and its predecessor funds, including the legacy-BlackRock funds. He served as U.S. Ambassador to the European Union, Under Secretary of Commerce for International Trade, Under Secretary of State for Economic, Business & Agricultural Affairs, and Deputy Secretary of the U.S. Treasury during the Clinton Administration. He was Director of the White House Domestic Policy Staff and Chief Domestic Policy Adviser to President Carter. In addition, Mr. Eizenstat is a practicing attorney and Head of the International Practice at a major international law firm. Mr. Eizenstat has business and executive management experience and corporate governance experience through his service on the advisory boards and corporate boards of publicly-held consumer, energy, environmental delivery, metallurgical and telecommunications companies.
Henry Gabbay	Henry Gabbay’s many years of experience in finance provide the Board with a wealth of practical business knowledge and leadership. In particular, Mr. Gabbay’s experience as a Consultant for and Managing Director of BlackRock, Inc., Chief Administrative Officer of BlackRock Advisors, LLC and President of BlackRock Funds provides the Funds with greater insight into the analysis and evaluation of both their existing investment portfolios and potential future investments as well as enhanced oversight of their investment decisions and investment valuation processes. In addition, Mr. Gabbay’s former positions as Chief Administrative Officer of BlackRock Advisors, LLC and as Treasurer of certain closed-end funds in the BlackRock Fund Complex provide the Board with direct knowledge of the operations of the BlackRock-advised Funds and their investment adviser. Mr. Gabbay’s previous service on and long-standing relationship with the Board also provide him with a specific understanding of the BlackRock-advised Funds, their operations, and the business and regulatory issues facing the BlackRock-advised Funds.
Lena G. Goldberg	Lena G. Goldberg has more than 20 years of business and oversight experience, most recently through her service as a senior lecturer at Harvard Business School. Prior thereto, she held legal and management positions at FMR LLC/Fidelity Investments as well as positions on the boards of various Fidelity subsidiaries over a 12-year period. She has additional corporate governance experience as a member of board and advisory committees for privately held corporations and non-profit organizations. Ms. Goldberg also has more than 17 years of legal experience as an attorney in private practice, including as a partner in a law firm.
Robert M. Hernandez	Robert M. Hernandez has served for approximately 23 years on the board of registered investment companies, having served as Chair of the Board of the Equity-Bond Complex and as Vice Chairman and Chairman of the Audit and Nominating/Governance Committees of its predecessor funds, including certain legacy-BlackRock funds. Mr. Hernandez has business and executive experience through his service as group president, chief financial officer, Chairman and vice chairman, among other positions, of publicly-held energy, steel, and metal companies. He has served as a director of other public companies in various industries throughout his career. He also has broad corporate governance experience, having served as a board member of publicly-held energy, insurance, chemicals, metals and electronics companies. Mr. Hernandez has been determined by the Audit Committee to be an audit committee financial expert, as such term is defined in the applicable SEC rules.
Henry R. Keizer	Henry R. Keizer has executive, financial, operational, strategic and global expertise from his 35 year career at KPMG, a global professional services organization. He has extensive experience with issues facing complex, global companies and expertise in financial reporting, accounting, auditing, risk management, and regulatory affairs for such companies. Mr. Keizer’s experience also includes service as a director and audit committee chair to both publicly and privately held organizations across numerous industries including professional services, property and casualty reinsurance, insurance, diversified financial services, banking, direct to consumer, business to business and technology. Mr. Keizer is a certified public accountant and also served on the board of the American Institute of Certified Public Accountants. Mr. Keizer has been determined by the Audit Committee to be an audit committee financial expert, as such term is defined in the applicable SEC rules.

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Directors	Experience, Qualifications and Skills
John F. O’Brien	John F. O’Brien has served for approximately 12 years on the board of registered investment companies, having served as a member of the Board of the Equity-Bond Complex and its predecessor funds, including the legacy-MLIM funds. He also has investment management experience, having served as the president, director, and chairman of the board of an investment management firm and a life insurance company. Mr. O’Brien also has broad corporate governance and audit committee experience, having served as a board member and audit committee member of publicly-held financial, medical, energy, chemical, retail, life insurance and auto parts manufacturing companies, and as a director of a not-for-profit organization.
Donald C. Opatrny	Donald C. Opatrny has more than 39 years of business, oversight and executive experience, including through his service as president, director and investment committee chair for academic and not-for-profit organizations, and his experience as a partner, managing director and advisory director at Goldman Sachs for 32 years. He also has investment management experience as a board member of Athena Capital Advisors LLC.
Interested Directors
Robert Fairbairn	Robert Fairbairn has more than 20 years of experience with BlackRock, Inc. and over 28 years in finance and asset management. In particular, Mr. Fairbairn’s positions as Senior Managing Director of BlackRock, Inc., Global Head of BlackRock’s Retail and iShares® businesses, and Member of BlackRock’s Global Executive and Global Operating Committees provide the Board with a wealth of practical business knowledge and leadership. In addition, Mr. Fairbairn has global investment management and oversight experience through his former positions as Head of BlackRock’s Global Client Group and Chairman of BlackRock’s international businesses. Prior to joining BlackRock, Mr. Fairbairn was Senior Vice President and Head of the EMEA Pacific region at MLIM, a member of the MLIM Executive Committee, head of the EMEA Sales Division and Chief Operating Officer of the EMEA Pacific region.
John M. Perlowski	John M. Perlowski’s experience as Managing Director of BlackRock, Inc. since 2009, as the Head of BlackRock Global Fund & Accounting Services since 2009, and as President and Chief Executive Officer of the BlackRock-advised Funds provides him with a strong understanding of the BlackRock-advised Funds, their operations, and the business and regulatory issues facing the BlackRock-advised Funds. Mr. Perlowski’s prior position as Managing Director and Chief Operating Officer of the Global Product Group at Goldman Sachs Asset Management, and his former service as Treasurer and Senior Vice President of the Goldman Sachs Mutual Funds and as Director of the Goldman Sachs Offshore Funds provides the Board with the benefit of his experience with the management practices of other financial companies.

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Biographical Information

Certain biographical and other information relating to the Directors is set forth below, including their address and year of birth, principal occupations for at least the last five years, length of time served, total number of registered investment companies and investment portfolios overseen in the BlackRock-advised Funds and any currently held public company and investment company directorships.

Name and Year of Birth1,2	Position(s)  Held (Length of Service)3	Principal Occupation(s) During Past Five Years	Number of BlackRock- Advised Registered Investment Companies (“RICs”) Consisting of Investment Portfolios (“Portfolios”) Overseen	Public  Company and Other Investment Company Directorships Held During Past Five Years
Independent Directors
Robert M. Hernandez 1944	Chair of the Board and Director (Since 2007)	Director, Vice Chairman and Chief Financial Officer of USX Corporation (energy and steel business) from 1991 to 2001; Director, RTI International Metals, Inc. from 1990 to 2015; Director, TE Connectivity (electronics) from 2006 to 2012.	27 RICs consisting of 98 Portfolios	Chubb Limited (insurance company); Eastman Chemical Company
James H. Bodurtha 1944	Director (Since 2007)	Director, The China Business Group, Inc. (consulting and investing firm) from 1996 to 2013 and Executive Vice President thereof from 1996 to 2003; Chairman of the Board, Berkshire Holding Corporation since 1980; Director, ICI Mutual since 2010.	27 RICs consisting of 98 Portfolios	None
Bruce R. Bond 1946	Director (Since 2007)	Trustee and Member of the Governance Committee, State Street Research Mutual Funds from 1997 to 2005; Board Member of Governance, Audit and Finance Committee, Avaya Inc. (computer equipment) from 2003 to 2007.	27 RICs consisting of 98 Portfolios	None
Honorable Stuart E. Eizenstat 1943	Director (Since 2007)	Partner and Head of International Practice, Covington and Burling LLP (law firm) since 2001; International Advisory Board Member, The Coca-Cola Company from 2002 to 2011; Advisory Board Member, Veracity Worldwide, LLC (risk management) from 2007 to 2012; Member of the International Advisory Board, GML Ltd. (energy) since 2003.	27 RICs consisting of 98 Portfolios	Alcatel-Lucent (telecommunications); Global Specialty Metallurgical; UPS Corporation (delivery service); Ferroglobe (metals)
Henry Gabbay 1947	Director (Since 2007)	Consultant, BlackRock, Inc. from 2007 to 2008; Managing Director, BlackRock, Inc. from 1989 to 2007; Chief Administrative Officer, BlackRock Advisors, LLC from 1998 to 2007; President of BlackRock Funds and BlackRock Allocation Target Shares (formerly, BlackRock Bond Allocation Target Shares) from 2005 to 2007 and Treasurer of certain closed-end funds in the BlackRock fund complex from 1989 to 2006.	27 RICs consisting of 98 Portfolios	None
Lena G. Goldberg 1949	Director (Since 2016)	Senior Lecturer, Harvard Business School, since 2008; Executive Vice President, FMR LLC/Fidelity Investments (financial services) from 2007 to 2008, Executive Vice President and General Counsel thereof from 2002 to 2007, Senior Vice President and General Counsel thereof from 1999 to 2002, Vice President and General Counsel thereof from 1997 to 1999, Senior Vice President and Deputy General Counsel thereof in 1997, and Vice President and Corporate Counsel thereof from 1996 to 1997; Partner, Sullivan & Worcester LLP from 1985 to 1996 and Associate thereof from 1979 to 1985.	27 RICs consisting of 98 Portfolios	None

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Name and Year of Birth1,2	Position(s)  Held (Length of Service)3	Principal Occupation(s) During Past Five Years	Number of BlackRock- Advised Registered Investment Companies (“RICs”) Consisting of Investment Portfolios (“Portfolios”) Overseen	Public  Company and Other Investment Company Directorships Held During Past Five Years
Henry R. Keizer 1956	Director (Since 2016)	Director, Park Indemnity Ltd. (captive insurer) since 2010; Director, MUFG Americas Holdings Corporation and MUFG Union Bank, N.A. (financial and bank holding company) from 2014 to 2016; Director, Montpelier Re Holdings, Ltd. (publicly held property and casual reinsurance) from 2013 to 2015; Director, American Institute of Certified Public Accountants from 2009 to 2011; Director, KPMG LLP (audit, tax and advisory services) from 2004 to 2005 and 2010 to 2012; Director, KPMG International in 2012, Deputy Chairman and Chief Operating Officer thereof from 2010 to 2012 and U.S. Vice Chairman of Audit thereof from 2005 to 2010; Global Head of Audit, KPMGI (consortium of KPMG firms) from 2006 to 2010; Director, YMCA of Greater New York from 2006 to 2010.	27 RICs consisting of 98 Portfolios	Hertz Global Holdings (car rental); WABCO (commercial vehicle safety systems)
John F. O’Brien 1943	Director (Since 2007)	Trustee, Woods Hole Oceanographic Institute since 2003 and Chairman thereof from 2009 to 2015; Co-Founder and Managing Director, Board Leaders LLC (director education) since 2005.	27 RICs consisting of 98 Portfolios	Cabot Corporation (chemicals); LKQ Corporation (auto parts manufacturing); TJX Companies, Inc. (retailer)
Donald C. Opatrny 1952	Director (Since 2015)	Trustee, Member of the Executive Committee and Chair of the Investment Committee, Cornell University since 2004; Member of the Board and Investment Committee, University School since 2007; Member of the Investment Committee, Mellon Foundation from 2009 to 2015; President and Trustee, the Center for the Arts, Jackson Hole since 2011; Director, Athena Capital Advisors LLC (investment management firm) since 2013; Trustee and Chair of the Investment Committee, Community Foundation of Jackson Hole since 2014; Trustee, Artstor (a Mellon Foundation affiliate) from 2010 to 2015; President, Trustee and Member of the Investment Committee, The Aldrich Contemporary Art Museum from 2007 to 2014.	27 RICs consisting of 98 Portfolios	None
Interested Directors4
Robert Fairbairn 1965	Director (Since 2015)	Senior Managing Director of BlackRock, Inc. since 2010; Global Head of BlackRock’s Retail and iShares®businesses since 2012; Member of BlackRock’s Global Executive and Global Operating Committees; Head of BlackRock’s Global Client Group from 2009 to 2012; Chairman of BlackRock’s international businesses from 2007 to 2010.	27 RICs consisting of 98 Portfolios	None
John M. Perlowski 1964	Director (Since 2015) and President and Chief Executive Officer and (Since 2010)	Managing Director of BlackRock, Inc. since 2009; Head of BlackRock Global Fund & Accounting Services since 2009; Managing Director and Chief Operating Officer of the Global Product Group at Goldman Sachs Asset Management, L.P. from 2003 to 2009; Treasurer of Goldman Sachs Mutual Funds from 2003 to 2009 and Senior Vice President thereof from 2007 to 2009; Director of Goldman Sachs Offshore Funds from 2002 to 2009; Advisory Director of Family Resource Network (charitable foundation) since 2009.	127 RICs consisting of 316 Portfolios	None

¹  The address of each Director is c/o BlackRock, Inc., 55 East 52^nd Street, New York, NY 10055.

²  Each Independent Director holds office until his or her successor is duly elected and qualifies or until his or her earlier death, resignation, retirement or removal as provided by the Corporation’s by-laws or charter or statute, or until December 31 of the year in which he or she turns 75. The Board may determine to extend the terms of Independent Directors on a case-by-case

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basis, as appropriate. Interested Directors serve until their successor is duly elected and qualifies or until their earlier death, resignation, retirement or removal as provided by the Corporation’s by-laws or statute, or until December 31 of the year in which they turn 72.

³  Following the combination of MLIM and BlackRock, Inc. in September 2006, the various legacy MLIM and legacy BlackRock fund boards were realigned and consolidated into three new fund boards in 2007. As a result, although the chart shows certain Independent Directors as joining the Corporation’s board in 2007, those Directors first became members of the boards of other legacy MLIM or legacy BlackRock funds as follows: James H. Bodurtha, 1995; Bruce R. Bond, 2005; Honorable Stuart E. Eizenstat, 2001; Robert M. Hernandez, 1996; and John F. O’Brien, 2005.

⁴  Messrs. Fairbairn and Perlowski are both “interested persons,” as defined in the Investment Company Act, of the Corporation based on their positions with BlackRock, Inc. and its affiliates. Mr. Perlowski is also a board member of the BlackRock Closed-End Complex and the BlackRock Equity-Liquidity Complex.

Certain biographical and other information relating to the officers of the Corporation who are not Directors/Trustees is set forth below, including their address and year of birth, principal occupations for at least the last five years and length of time served.

Name and Year of Birth1,2	Position(s) Held (Length of Service)	Principal Occupation(s) During Past Five Years
Officers Who Are Not Directors
Jennifer McGovern 1977	Vice President (Since 2014)	Managing Director of BlackRock, Inc. since 2016; Director of BlackRock, Inc. from 2011 to 2015; Head of Product Structure and Oversight for BlackRock’s U.S. Wealth Advisory Group since 2013; Vice President of BlackRock, Inc. from 2008 to 2010.
Neal J. Andrews 1966	Chief Financial Officer (Since 2007)	Managing Director of BlackRock, Inc. since 2006; Senior Vice President and Line of Business Head of Fund Accounting and Administration at PNC Global Investment Servicing (U.S.) Inc. from 1992 to 2006.
Jay M. Fife 1970	Treasurer (Since 2007)	Managing Director of BlackRock, Inc. since 2007; Director of BlackRock, Inc. in 2006; Assistant Treasurer of the MLIM and Fund Asset Management, L.P. advised funds from 2005 to 2006; Director of MLIM Fund Services Group from 2001 to 2006.
Charles Park 1967	Chief Compliance Officer (Since 2014)	Anti-Money Laundering Compliance Officer for the BlackRock-advised Funds in the Equity-Bond Complex, the Equity-Liquidity Complex and the Closed-End Complex from 2014 to 2015; Chief Compliance Officer of BlackRock Advisors, LLC and the BlackRock-advised Funds in the Equity-Bond Complex, the Equity-Liquidity Complex and the Closed-End Complex since 2014; Principal of and Chief Compliance Officer for iShares® Delaware Trust Sponsor LLC since 2012 and BlackRock Fund Advisors (“BFA”) since 2006; Chief Compliance Officer for the BFA-advised iShares® exchange traded funds since 2006; Chief Compliance Officer for BlackRock Asset Management International Inc. since 2012.
Fernanda Piedra 1969	Anti-Money Laundering Compliance Officer (Since 2015)	Director of BlackRock, Inc. since 2014; Anti-Money Laundering Compliance Officer and Regional Head of Financial Crime for the Americas at BlackRock, Inc. since 2014; Head of Regulatory Changes and Remediation for the Asset Wealth Management Division of Deutsche Bank from 2010 to 2014; Vice President of Goldman Sachs (Anti-Money Laundering/Suspicious Activities Group) from 2004 to 2010.
Benjamin Archibald 1975	Secretary (Since 2012)	Managing Director of BlackRock, Inc. since 2014; Director of BlackRock, Inc. from 2010 to 2013; Secretary of the iShares®exchange traded funds since 2015; Secretary of the BlackRock-advised mutual funds since 2012.

¹  The address of each Officer is c/o BlackRock, Inc., 55 East 52^nd Street, New York, NY 10055.

²  Officers of the Corporation serve at the pleasure of the Board.

Share Ownership

Information relating to each Director’s share ownership in each Fund and in all BlackRock-advised Funds that are overseen by the respective Director as of December 31, 2017 is set forth in the chart below.

Name of Director	Aggregate Dollar Range of Equity Securities in the High Yield Fund	Aggregate Dollar Range of Equity Securities in BlackRock- advised Funds
Interested Directors:
Robert Fairbairn	None	Over $100,000
John M. Perlowski	None	Over $100,000

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Name of Director	Aggregate Dollar Range of Equity Securities in the High Yield Fund	Aggregate Dollar Range of Equity Securities in BlackRock- advised Funds
Independent Directors:
James H. Bodurtha	None	Over $100,000
Bruce R. Bond	None	Over $100,000
Honorable Stuart E. Eizenstat	None	Over $100,000
Henry Gabbay	None	Over $100,000
Lena G. Goldberg	None	Over $100,000
Robert M. Hernandez	None	Over $100,000
Henry R. Keizer	$10,001-$50,000	Over $100,000
John F. O’Brien	None	Over $100,000
Donald C. Opatrny	None	Over $100,000

As of January 5, 2018, the Directors and officers of the Corporation as a group owned an aggregate of less than 1% of any class of the outstanding shares of each Fund. As of December 31, 2017, none of the Independent Directors of the Corporation or their immediate family members owned beneficially or of record any securities of the Funds’ investment adviser, principal underwriter, or any person directly or indirectly controlling, controlled by, or under common control with such entities.

Compensation of Directors

Each Director who is an Independent Director is paid as compensation an annual retainer of $200,000 per year for his or her services as a Board member of the BlackRock-advised Funds, including the Funds, and a $25,000 Board meeting fee to be paid for each Board meeting up to five in-person Board meetings held in a calendar year (compensation for meetings in excess of this number to be determined on a case-by-case basis), together with out-of-pocket expenses in accordance with a Board policy on travel and other business expenses relating to attendance at meetings. The Chair of the Board may, in consultation with the Chair of the Governance Committee, determine that the Independent Directors be paid a fee of $5,000 per meeting for certain telephonic Board meetings. In addition, the Chair is paid as compensation an additional annual retainer of $115,000 per year. The Chairs of the Audit Committee, Compliance Committee, Governance Committee and Performance Committee are paid as compensation an additional annual retainer of $35,000, respectively.

The following table sets forth the compensation paid to the Directors by the Corporation, on behalf of the Funds, for the fiscal year ended June 30, 2017, and the aggregate compensation paid to them by all BlackRock-advised Funds for the calendar year ended December 31, 2017.

Name 1	Aggregate  Compensation from the High Yield Fund	Estimated Annual Benefits Upon Retirement	Aggregate Compensation from the Funds and Other BlackRock- Advised Funds
Interested Directors:2
Robert Fairbairn	None	None	None
John M. Perlowski	None	None	None
Independent Directors:
James H. Bodurtha3	$2,722	None	$380,000
Bruce R. Bond4	$2,645	None	$380,000
Donald W. Burton5	$2,581	None	$345,000
Honorable Stuart E. Eizenstat6	$2,657	None	$345,000
Henry Gabbay	$2,581	None	$345,000
Lena G. Goldberg7	$1,772	None	$331,667

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Name 1	Aggregate  Compensation from the High Yield Fund	Estimated Annual Benefits Upon Retirement	Aggregate Compensation from the Funds and Other BlackRock- Advised Funds
Robert M. Hernandez8	$2,745	None	$460,000
Henry R. Keizer9	$2,572	None	$376,986
John F. O’Brien	$2,581	None	$345,000
Donald C. Opatrny10	$2,645	None	$380,000
Roberta Cooper Ramo11	$2,581	None	$345,000
David H. Walsh12	$1,230	None	$17,222
Fred G. Weiss13	$1,359	None	$17,222

¹  For the number of BlackRock-advised Funds from which each Director receives compensation see the Biographical Information Chart beginning on page I-13.

²  Messrs. Fairbairn and Perlowski receive no compensation from the BlackRock-advised Funds for their service as Trustees/Directors.

³  Chair of the Compliance Committee through December 31, 2017.

⁴  Chair of the Governance Committee effective January 1, 2017.

⁵  Mr. Burton resigned as a Director of the Fund effective December 31, 2017.

⁶  Chair of the Governance Committee through December 31, 2016.

⁷  Chair of the Compliance Committee effective January 1, 2018. Ms. Goldberg was appointed to serve as a Director of the Corporation effective November 4, 2016.

⁸  Chair of the Board of Directors.

⁹  Chair of the Audit Committee effective February 1, 2017. Mr. Keizer was appointed to serve as a Director of the Corporation effective July 28, 2016.

¹⁰  Chair of the Performance Committee effective January 1, 2017.

¹¹  Ms. Ramo retired as a Director of the Corporation effective December 31, 2017.

¹²  Mr. Walsh retired as a Director of the Corporation effective January 31, 2017. Mr. Walsh served as Chairman of the Performance Committee through December 31, 2016.

¹³  Mr. Weiss retired as a Director of the Corporation effective January 31, 2017. Mr. Weiss served as Vice Chairman of the Board of Directors and Chairman of the Audit Committee through January 31, 2017.

IV. Management and Advisory Arrangements

The Corporation, on behalf of the High Yield Fund, has entered into an investment advisory agreement with BlackRock Advisors, LLC pursuant to which the Manager receives as compensation for its services to the Fund, a fee with respect to the Fund at the end of each month at the rates described below. The investment advisory agreement between the Manager and the Corporation is referred to as the “Management Agreement.”

Effective November 1, 2016, the annual advisory fee rate for the High Yield Fund is as follows:

	Management Fee Rate
Aggregate of average daily net assets of the Fund
Not exceeding $1 billion	0.47%
In excess of $1 billion but not exceeding $3 billion	0.44%
In excess of $3 billion but not exceeding $5 billion	0.42%
In excess of $5 billion but not exceeding $10 billion	0.41%
In excess of $10 billion	0.40%

Prior to November 1, 2016, with respect to the High Yield Fund, the annual advisory fee rate was as follows:

	Management Fee Rate
Aggregate of average daily net assets of the Fund
First $250 million	0.550%
$250 million — $500 million	0.525%
Greater than $500 million	0.500%

BlackRock has contractually agreed to waive the management fee with respect to any portion of the Fund’s assets estimated to be attributable to investments in other equity and fixed-income mutual funds and

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exchange-traded funds managed by BlackRock or its affiliates that have a contractual management fee, through October 31, 2019. The contractual agreement may be terminated upon 90 days’ notice by a majority of the Independent Directors or by a vote of a majority of the outstanding voting securities of the Fund.

The table below sets forth information about the total management fees paid by the Fund to the Manager, and the amounts waived and/or reimbursed by the Manager, for the periods indicated.

Fiscal Year Ended June 30,	Paid to the Manager	Waived by the Manager1,2	Reimbursements by the Manager2
2017	$3,923,775	$181,402	$158,187
2016	$3,394,139	$27,640	$9,342
2015	$2,915,229	$2,101	$0

¹  In addition to the contractual waivers described above, the Manager may voluntarily waive a portion of the Fund’s management fee in connection with the Fund’s investment in an affiliated money market fund.

²  The Manager has contractually agreed to waive and/or reimburse fees or expenses in order to limit expenses (excluding interest expenses, acquired fund fees and expenses and certain other fund expenses) to 0.49% (for Class K Shares) through October 31, 2019. This contractual agreement may be terminated upon 90 days’ notice by a majority of the non-interested directors of the Corporation or by a vote of a majority of the outstanding voting securities of the Fund.

Pursuant to the Management Agreement, the Manager may from time to time, in its sole discretion to the extent permitted by applicable law, appoint one or more sub-advisers, including, without limitation, affiliates of the Manager, to perform investment advisory services with respect to the Fund. In addition, the Manager may delegate certain of its investment advisory functions under the Management Agreement to one or more of its affiliates to the extent permitted by applicable law. The Manager may terminate any or all sub-advisers or such delegation arrangements in its sole discretion at any time to the extent permitted by applicable law.

Information Regarding the Portfolio Managers

Theodore R. Jaeckel, Jr. and Walter O’Connor are the portfolio managers of the High Yield Fund and are jointly and primarily responsible for the day-to-day operations of the Fund.

Other Funds and Accounts Managed

The following table sets forth information about funds and accounts other than the Fund for which the Fund’s portfolio managers are primarily responsible for the day-to-day portfolio management as of June 30, 2017.

	Number of Other Accounts Managed and Assets by Account Type			Number of Other Accounts and Assets for Which Advisory Fee is Performance-Based
Name of Portfolio Manager	Other  Registered Investment Companies	Other Pooled Investment Vehicles	Other  Accounts	Other  Registered Investment Companies	Other Pooled Investment Vehicles	Other  Accounts
Theodore R. Jaeckel, Jr., CFA	38	0	0	0	0	0
	$26.95 Billion	$0	$0	$0	$0	$0
Walter O’Connor, CFA	31	0	0	0	0	0
	$19.30 Billion	$0	$0	$0	$0	$0

Portfolio Manager Compensation Overview

The discussion below describes the portfolio managers’ compensation as of June 30, 2017.

BlackRock’s financial arrangements with its portfolio managers, its competitive compensation and its career path emphasis at all levels reflect the value senior management places on key resources. Compensation may include a variety of components and may vary from year to year based on a number of factors. The principal components of compensation include a base salary, a performance-based discretionary bonus, participation in various benefits programs and one or more of the incentive compensation programs established by BlackRock.

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Base Compensation. Generally, portfolio managers receive base compensation based on their position with the firm.

Discretionary Incentive Compensation

Discretionary incentive compensation is a function of several components: the performance of BlackRock, Inc., the performance of the portfolio manager’s group within BlackRock, the investment performance, including risk-adjusted returns, of the firm’s assets under management or supervision by that portfolio manager relative to predetermined benchmarks, and the individual’s performance and contribution to the overall performance of these portfolios and BlackRock. In most cases, these benchmarks are the same as the benchmark or benchmarks against which the performance of the Corporation or other accounts managed by the portfolio managers are measured. Among other things, BlackRock’s Chief Investment Officers make a subjective determination with respect to each portfolio manager’s compensation based on the performance of the Funds and other accounts managed by each portfolio manager relative to the various benchmarks. Performance of fixed-income funds is measured on a pre-tax and/or after-tax basis over various time periods including 1-, 3- and 5- year periods, as applicable. With respect to these portfolio managers, such benchmarks for the Fund and other accounts are:

Portfolio Manager	Benchmark
Theodore R. Jaeckel, Jr., CFA Walter O’ Connor, CFA	A combination of market-based indices (e.g., Standard & Poor’s Municipal Bond Index), certain customized indices and certain fund industry peer groups.

Distribution of Discretionary Incentive Compensation. Discretionary incentive compensation is distributed to portfolio managers in a combination of cash, deferred BlackRock, Inc. stock awards, and/or deferred cash awards that notionally track the return of certain BlackRock investment products.

Typically, the cash portion of the discretionary incentive compensation, when combined with base salary, represents more than 60% of total compensation for the portfolio managers.

Portfolio managers generally receive deferred BlackRock, Inc. stock awards as part of their discretionary incentive compensation. Paying a portion of discretionary incentive compensation in the form of deferred BlackRock, Inc. stock puts compensation earned by a portfolio manager for a given year “at risk” based on BlackRock’s ability to sustain and improve its performance over future periods. Deferred BlackRock, Inc. stock awards are generally granted in the form of BlackRock, Inc. restricted stock units that vest ratably over a number of years and, once vested, settle in BlackRock, Inc. common stock. In some cases, additional deferred BlackRock, Inc. stock may be granted to certain key employees as part of a long-term incentive award to aid in retention, align their interests with long-term shareholder interests and motivate performance. Such equity awards are generally granted in the form of BlackRock, Inc. restricted stock units that vest pursuant to the terms of the applicable plan and, once vested, settle in BlackRock, Inc. common stock. The portfolio managers of these Funds have deferred BlackRock, Inc. stock awards.

For some portfolio managers, discretionary incentive compensation is also distributed in the form of deferred cash awards that notionally track the returns of select BlackRock investment products they manage. Providing a portion of discretionary incentive compensation in deferred cash awards that notionally track the BlackRock investment products they manage provides direct alignment with investment product results. Deferred cash awards vest ratably over a number of years and, once vested, settle in the form of cash. Any portfolio manager who is either a managing director or director at BlackRock with compensation above a specified threshold is eligible to participate in the deferred compensation program.

Other Compensation Benefits. In addition to base salary and discretionary incentive compensation, portfolio managers may be eligible to receive or participate in one or more of the following:

Incentive Savings Plans — BlackRock, Inc. has created a variety of incentive savings plans in which BlackRock employees are eligible to participate, including a 401(k) plan, the BlackRock Retirement Savings Plan (RSP), and the BlackRock Employee Stock Purchase Plan (ESPP). The employer contribution

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components of the RSP include a company match equal to 50% of the first 8% of eligible pay contributed to the plan capped at $5,000 per year, and a company retirement contribution equal to 3-5% of eligible compensation up to the Internal Revenue Service limit ($270,000 for 2017). The RSP offers a range of investment options, including registered investment companies and collective investment funds managed by the firm. BlackRock contributions follow the investment direction set by participants for their own contributions or, absent participant investment direction, are invested into a target date fund that corresponds to, or is closest to, the year in which the participant attains age 65. The ESPP allows for investment in BlackRock common stock at a 5% discount on the fair market value of the stock on the purchase date. Annual participation in the ESPP is limited to the purchase of 1,000 shares of common stock or a dollar value of $25,000 based on its fair market value on the purchase date. All of the eligible portfolio managers are eligible to participate in these plans.

Portfolio Manager Beneficial Holdings

As of June 30, 2017, the end of the Fund’s most recently completed fiscal year end, the dollar range of securities of the Fund beneficially owned by each portfolio manager is shown below:

Portfolio Manager	Portfolio(s) Managed	Dollar Range of Equity Securities Owned
Theodore R. Jaeckel, Jr., CFA	High Yield Fund	$100,001-$500,000
Walter O’Connor, CFA	High Yield Fund	None

Portfolio Manager Potential Material Conflicts of Interest

BlackRock has built a professional working environment, firm-wide compliance culture and compliance procedures and systems designed to protect against potential incentives that may favor one account over another. BlackRock has adopted policies and procedures that address the allocation of investment opportunities, execution of portfolio transactions, personal trading by employees and other potential conflicts of interest that are designed to ensure that all client accounts are treated equitably over time. Nevertheless, BlackRock furnishes investment management and advisory services to numerous clients in addition to the Funds, and BlackRock may, consistent with applicable law, make investment recommendations to other clients or accounts (including accounts which are hedge funds or have performance or higher fees paid to BlackRock, or in which portfolio managers have a personal interest in the receipt of such fees), which may be the same as or different from those made to the Fund. In addition, BlackRock, its affiliates and significant shareholders and any officer, director, shareholder or employee may or may not have an interest in the securities whose purchase and sale BlackRock recommends to the Fund. BlackRock, or any of its affiliates or significant shareholders, or any officer, director, shareholder, employee or any member of their families may take different actions than those recommended to the Fund by BlackRock with respect to the same securities. Moreover, BlackRock may refrain from rendering any advice or services concerning securities of companies of which any of BlackRock’s (or its affiliates’ or significant shareholders’) officers, directors or employees are directors or officers, or companies as to which BlackRock or any of its affiliates or significant shareholders or the officers, directors and employees of any of them has any substantial economic interest or possesses material non-public information. Certain portfolio managers also may manage accounts whose investment strategies may at times be opposed to the strategy utilized for the Fund. It should also be noted that a portfolio manager may be managing hedge fund and/or long only accounts, or may be part of a team managing hedge fund and/or long only accounts, subject to incentive fees. Such portfolio managers may therefore be entitled to receive a portion of any incentive fees earned on such accounts. Currently, the portfolio managers of these funds are not entitled to receive a portion of incentive fees of other accounts.

As a fiduciary, BlackRock owes a duty of loyalty to its clients and must treat each client fairly. When BlackRock purchases or sells securities for more than one account, the trades must be allocated in a manner consistent with its fiduciary duties. BlackRock attempts to allocate investments in a fair and equitable manner among client accounts, with no account receiving preferential treatment. To this end, BlackRock has adopted

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policies that are intended to ensure reasonable efficiency in client transactions and provide BlackRock with sufficient flexibility to allocate investments in a manner that is consistent with the particular investment discipline and client base, as appropriate.

Custodian Services

State Street Bank and Trust Company (“State Street”) has been retained to act as custodian for the Fund and is located at One Lincoln Street, Boston, Massachusetts 02111. The custodian, among other things, maintains a custody account or accounts in the name of the Fund, receives and delivers all assets for the Fund upon purchase and upon sale or maturity, and collects and receives all income and other payments and distributions on account of the assets of the Fund.

Transfer Agency and Shareholders’ Administrative Services

BNY Mellon Investment Servicing (US) Inc. (“BNY Mellon”), which has its principal place of business at 301 Bellevue Parkway, Wilmington, Delaware 19809, serves as the transfer and dividend disbursement agent for the Fund.

Pursuant to a Shareholders’ Administrative Services Agreement, the Manager provides certain shareholder liaison services in connection with the Fund’s investor service center. The Fund reimburses the Manager for its costs in maintaining the service center, which costs include, among other things, employee salaries, leasehold expenses, and other out-of-pocket expenses which are a component of the transfer agency fees in the Fund’s annual report.

Set forth below are the amounts the Fund reimbursed BlackRock pursuant to the Shareholders’ Administrative Services Agreement for the periods indicated:

Fiscal Year Ended June 30,	High Yield Fund
2017
Paid to the Manager		$4,047
2016
Paid to the Manager		$3,523
2015
Paid to the Manager		$3,402

Accounting Services

The table below shows the amounts paid by the Fund to State Street and the Manager for accounting services for the periods indicated:

Fiscal Year Ended June 30,	High Yield Fund
2017
Paid to State Street		$159,820
Paid to the Manager		$10,852
2016
Paid to State Street		$117,752
Paid to the Manager		$6,489
2015
Paid to State Street		$125,929
Paid to the Manager		$6,061

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Credit Agreement

The Corporation, on behalf of the Fund, along with certain other funds managed by the Manager and its affiliates (“Participating Funds”), is a party to a 364-day, $2.1 billion credit agreement with a group of lenders, which facility terminates on April 19, 2018 unless otherwise extended or renewed (the “Credit Agreement”). Excluding commitments designated for certain funds, other Participating Funds, including the Funds, can borrow up to an aggregate commitment amount of $1.6 billion at any time outstanding, subject to asset coverage and other limitations as specified in the Credit Agreement. The Fund may borrow under the Credit Agreement to meet shareholder redemptions and for other lawful purposes. The Fund may not borrow under the Credit Agreement for leverage. The Fund may borrow up to the maximum amount allowable under the Funds’ current Prospectus and SAI, subject to various other legal, regulatory or contractual limits. Borrowing results in interest expense and other fees and expenses for the Fund which may impact the Funds’ net expenses. The costs of borrowing may reduce the Fund’s returns. The Fund is charged its pro rata share of upfront fees and commitment fees on the aggregate commitment amount based on its net assets. If the Funds borrow pursuant to the Credit Agreement, the Funds is charged interest at a variable rate.

V. Computation of Offering Price Per Share

The offering price for the Fund’s Class K Shares is equal to the net asset value computed by dividing the value of the Class K Shares’ net assets by the number of shares outstanding. For more information on the purchasing and valuation of shares, please see “Purchase of Shares” and “Pricing of Shares” in Part II of this SAI.

VI. Portfolio Transactions and Brokerage

See “Portfolio Transactions and Brokerage” in Part II of this Statement of Additional Information for more information.

For the periods indicated, the Fund paid total brokerage commissions as set forth below.

Fiscal Year Ended June 30,	Total Brokerage Commissions Paid	Commissions Paid to Affiliates
2017	$6,600	$0
2016	$4,443	$0
2015	$4,714	$0

As of June 30, 2017, the Fund held no securities of its regular brokers or dealers (as defined in Rule 10b-1 under the Investment Company Act) whose shares were purchased during the fiscal year ended June 30, 2017.

Securities Lending

The Fund conducts its securities lending pursuant to an exemptive order from the Commission permitting it to lend portfolio securities to borrowers affiliated with the Fund and to retain an affiliate of the Fund as lending agent. To the extent that Fund engages in securities lending, BlackRock Investment Management, LLC (“BIM”), an affiliate of the Manager, acts as securities lending agent for the Fund, subject to the overall supervision of the Manager. BIM administers the lending program in accordance with guidelines approved by the Board.

To the extent the Fund engages in securities lending, the Fund retains a portion of securities lending income and remits a remaining portion to BIM as compensation for its services as securities lending agent. Securities lending income is equal to the total of income earned from the reinvestment of cash collateral (and excludes collateral investment expenses as defined below), and any fees or other payments to and from borrowers of securities. As securities lending agent, BIM bears all operational costs directly related to securities lending. The Fund is responsible for expenses in connection with the investment of cash collateral received for securities on loan (the “collateral investment expenses”). The cash collateral is invested in a private investment company

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managed by the Manager or its affiliates. However, BIM has agreed to cap the collateral investment expenses of the private investment company to an annual rate of 0.04%. In addition, in accordance with the exemptive order, the investment adviser to the private investment company will not charge any advisory fees with respect to shares purchased by the Fund. Such shares also will not be subject to a sales load, distribution fee or service fee. If the private investment company’s weekly liquid assets fall below 30% of its total assets, BIM, as managing member of the private investment company, is permitted at any time, if it determines it to be in the best interests of the private investment company, to impose a liquidity fee of up to 2% of the value of units withdrawn or impose a redemption gate that temporarily suspends the right of withdrawal out of the private investment company. In addition, if the private investment company’s weekly liquid assets fall below 10% of its total assets at the end of any business day, the private investment company will impose a liquidity fee in the default amount of 1% of the amount withdrawn, generally effective as of the next business day, unless BIM determines that a higher (not to exceed 2%) or lower fee level or not imposing a liquidity fee is in the best interests of the private investment company. The shares of the private investment company purchased by the Fund would be subject to any such liquidity fee or redemption gate imposed.

Pursuant to the current securities lending agreement: (i) if the Fund were to engage in securities lending, the Fund retains 80% of securities lending income (which excludes collateral investment expenses), and (ii) this amount can never be less than 70% of the sum of securities lending income plus collateral investment expenses.

Under the securities lending program, the Fund is categorized into specific asset classes. The determination of the Fund’s asset class category (fixed income, domestic equity, international equity, or fund of funds), each of which may be subject to a different fee arrangement, is based on a methodology agreed to between the Corporation and BIM.

In addition, commencing the business day following the date that the aggregate securities lending income earned across the Equity-Bond Complex in a calendar year exceeds a specified threshold, the Fund, pursuant to the current securities lending agreement, will receive for the remainder of that calendar year securities lending income as follows: (i) if the Fund was to engage in securities lending, 85% of securities lending income (which excludes collateral investment expenses); and (ii) this amount can never be less than 70% of the sum of securities lending income plus collateral investment expenses.

The Fund paid no security lending agent fees to the lending agent during the fiscal years ended June 30, 2017, June 30, 2016 and June 30, 2015.

VII. Additional Information

Description of Shares

The Corporation is a diversified, open-end management investment company organized under the laws of the State of Maryland that commenced operations on October 21, 1977. Prior to September 21, 1979, the Corporation consisted solely of the Municipal Fund. Currently, the Corporation is comprised of three separate funds: National Fund, Short-Term Fund and High Yield Fund.

Effective September 29, 2006, the Corporation changed its name to BlackRock Municipal Bond Fund, Inc., and National Portfolio, Short-Term Portfolio and High Yield Portfolio changed their names to BlackRock National Municipal Fund, BlackRock Short-Term Municipal Fund and BlackRock High Yield Municipal Fund, respectively.

The authorized capital stock of the National Fund consists of 3,275,000,000 shares of Common Stock, par value $0.10 per share, divided into seven classes. The Investor A and Institutional classes each consist of 800,000,000 shares. The Investor C, Investor C1, Class K and Service classes each consist of 375,000,000 shares. The Investor B class consists of 175,000,000 shares. The authorized capital stock of the Short-Term Fund consists of 900,000,000 shares of Common Stock, par value $0.10 per share, divided into six classes. The Investor A, Investor A1, Investor C, Institutional, Class K and Service classes each consist of 150,000,000 shares. The authorized capital stock of the High Yield Fund consists of 2,300,000,000 shares of Common

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Stock, par value $0.10 per share, divided into four classes. The Investor A, Investor C, and Institutional classes each consist of 100,000,000 shares. The Class K class consists of 2,000,000,000 shares. The Board of Directors approved the conversion of all of the issued and outstanding Investor B Shares of the National Fund into Investor A Shares of the National Fund, effective on the close of business on December 27, 2017.

Each of the Corporation’s shares have equal dividend, distribution, liquidation and voting rights, except that only shares of each respective Fund are entitled to vote on matters concerning only that Fund and Investor A, Investor A1, Investor B, Investor B1, Investor C and Investor C1 Shares bear certain shareholder servicing expenses and/or expenses related to the distribution of such shares and have exclusive voting rights with respect to matters relating to such shareholder servicing and distribution expenditures (except that Investor B shareholders may vote upon material changes to expenses charged under the Investor A (and Investor A1 for the Short-Term Fund) Distribution Plan).

Miscellaneous

Counsel. Willkie Farr & Gallagher LLP, 787 Seventh Avenue, New York, New York 10019 serves as the Funds’ counsel.

Independent Registered Public Accounting Firm. Deloitte & Touche LLP, with offices located at 200 Berkeley Street, Boston, MA 02116 serves as the Funds’ independent registered public accounting firm.

Principal Shareholders

To the knowledge of the Corporation, the following entities owned of record or beneficially 5% or more of a class of the Fund’s shares as of January 5, 2018:

Merrill Lynch Pierce Fenner & Smith Incorporated	4800 Deer Lake Drive East Jacksonville, FL 32246-6484	23.11%	Investor A Shares
Edward D. Jones and Co. for the Benefit of Customers	12555 Manchester Road St. Louis, MO 63131-3710	17.47%	Investor A Shares
Morgan Stanley & Co.	Harborside Financial Center Plaza II 3rd Floor Jersey City, NJ 07311	9.19%	Investor A Shares
NFS LLC FEBO	499 Washington Blvd Jersey City, NJ 07310	8.77%	Investor A Shares
UBS WM USA	1000 Harbor Blvd Weehawken, NJ 07086	8.97%	Investor A Shares
Pershing LLC	1 Pershing Plaza Jersey City, NJ 07399-0001	6.34%	Investor A Shares
Wells Fargo Clearing Services	2801 Market Street St. Louis, MO 63103	6.97%	Investor A Shares
Merrill Lynch Pierce Fenner & Smith Incorporated	4800 Deer Lake Drive East Jacksonville, FL 32246-6484	31.91%	Investor C Shares
Morgan Stanley & Co.	Harborside Financial Center Plaza II 3rd Floor Jersey City, NJ 07311	12.65%	Investor C Shares
Wells Fargo Clearing Services	2801 Market Street St. Louis, MO 63103	11.53%	Investor C Shares
UBS WM USA	1000 Harbor Blvd Weehawken, NJ 07086	10.15%	Investor C Shares
Pershing LLC	1 Pershing Plaza Jersey City, NJ 07399-0001	6.68%	Investor C Shares
Edward D. Jones and Co. for the Benefit of Customers	12555 Manchester Road St. Louis, MO 63131-3710	5.91%	Investor C Shares
Merrill Lynch Pierce Fenner & Smith Incorporated	4800 Deer Lake Drive East Jacksonville, FL 32246-6484	43.16%	Institutional Class

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Charles Schwab and Co, Inc.	101 Montgomery Street San Francisco, CA 94104-4122	10.61%	Institutional Class
NFS LLC FEBO	499 Washington Blvd Jersey City, NJ 07310	7.54%	Institutional Class
UBS WM USA	1000 Harbor Blvd Weehawken, NJ 07086	6.81%	Institutional Class
Morgan Stanley & Co	Harborside Financial Center Plaza II 3rd Floor Jersey City, NJ 07311	5.23%	Institutional Class

VIII. Financial Statements

The audited financial statements and notes thereto in the Fund’s Annual Report to Shareholders for the fiscal year ended June 30, 2017 (the “2017 Annual Report”) are incorporated in this Statement of Additional Information by reference. No other parts of the 2017 Annual Report are incorporated by reference herein. The financial statements included in the 2017 Annual Report have been audited by Deloitte & Touche LLP. The report of Deloitte & Touche LLP is incorporated herein by reference. Such financial statements have been incorporated herein in reliance upon the report of such firm given their authority as experts in accounting and auditing. Additional copies of the 2017 Annual Report may be obtained at no charge by telephoning the Distributor at the telephone number appearing on the front page of this Statement of Additional Information.

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APPENDIX A

Description of Bond Ratings

A Description of Moody’s Investors Service, Inc.’s (“Moody’s”) Global Rating Scales

Ratings assigned on Moody’s global long-term and short-term rating scales are forward-looking opinions of the relative credit risks of financial obligations issued by non-financial corporates, financial institutions, structured finance vehicles, project finance vehicles, and public sector entities. Long-term ratings are assigned to issuers or obligations with an original maturity of one year or more and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default. Short-term ratings are assigned to obligations with an original maturity of thirteen months or less and reflect both on the likelihood of a default on contractually promised payments and the expected financial loss suffered in the event of default.

Description of Moody’s Long-Term Obligation Ratings

Aaa	Obligations rated Aaa are judged to be of the highest quality, subject to the lowest level of credit risk.
Aa	Obligations rated Aa are judged to be of high quality and are subject to very low credit risk.
A	Obligations rated A are judged to be upper-medium grade and are subject to low credit risk.
Baa	Obligations rated Baa are judged to be medium-grade and subject to moderate credit risk and as such may possess certain speculative characteristics.
Ba	Obligations rated Ba are judged to be speculative and are subject to substantial credit risk.
B	Obligations rated B are considered speculative and are subject to high credit risk.
Caa	Obligations rated Caa are judged to be speculative of poor standing and are subject to very high credit risk.
Ca	Obligations rated Ca are highly speculative and are likely in, or very near, default, with some prospect of recovery of principal and interest.
C	Obligations rated C are the lowest rated and are typically in default, with little prospect for recovery of principal or interest.

Note: Moody’s appends numerical modifiers 1, 2, and 3 to each generic rating classification from Aa through Caa. The modifier 1 indicates that the obligation ranks in the higher end of its generic rating category; the modifier 2 indicates a mid-range ranking; and the modifier 3 indicates a ranking in the lower end of that generic rating category.

Hybrid Indicator (hyb)

The hybrid indicator (hyb) is appended to all ratings of hybrid securities issued by banks, insurers, finance companies, and securities firms. By their terms, hybrid securities allow for the omission of scheduled dividends, interest, or principal payments, which can potentially result in impairment if such an omission occurs. Hybrid securities may also be subject to contractually allowable write-downs of principal that could result in impairment. Together with the hybrid indicator, the long-term obligation rating assigned to a hybrid security is an expression of the relative credit risk associated with that security.

Description of Short-Term Obligation Ratings

Moody’s employs the following designations to indicate the relative repayment ability of rated issuers:

P-1	Issuers (or supporting institutions) rated Prime-1 have a superior ability to repay short-term debt obligations.
P-2	Issuers (or supporting institutions) rated Prime-2 have a strong ability to repay short-term debt obligations.
P-3	Issuers (or supporting institutions) rated Prime-3 have an acceptable ability to repay short-term obligations.
NP	Issuers (or supporting institutions) rated Not Prime do not fall within any of the Prime rating categories.

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Description of Moody’s US Municipal Short-Term Obligation Ratings

The Municipal Investment Grade (“MIG”) scale is used to rate US municipal bond anticipation notes of up to three years maturity. Municipal notes rated on the MIG scale may be secured by either pledged revenues or proceeds of a take-out financing received prior to note maturity. MIG ratings expire at the maturity of the obligation, and the issuer’s long-term rating is only one consideration in assigning the MIG rating. MIG ratings are divided into three levels — MIG 1 through MIG 3 — while speculative grade short-term obligations are designated SG.

MIG 1	This designation denotes superior credit quality. Excellent protection is afforded by established cash flows, highly reliable liquidity support, or demonstrated broad-based access to the market for refinancing.
MIG 2	This designation denotes strong credit quality. Margins of protection are ample, although not as large as in the preceding group.
MIG 3	This designation denotes acceptable credit quality. Liquidity and cash-flow protection may be narrow, and market access for refinancing is likely to be less well-established.
SG	This designation denotes speculative-grade credit quality. Debt instruments in this category may lack sufficient margins of protection.

Description of Moody’s Demand Obligation Ratings

In the case of variable rate demand obligations (“VRDOs”), a two-component rating is assigned: a long or short-term debt rating and a demand obligation rating. The first element represents Moody’s evaluation of risk associated with scheduled principal and interest payments. The second element represents Moody’s evaluation of risk associated with the ability to receive purchase price upon demand (“demand feature”). The second element uses a rating from a variation of the MIG scale called the Variable Municipal Investment Grade (“VMIG”) scale.

VMIG 1	This designation denotes superior credit quality. Excellent protection is afforded by the superior short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.
VMIG 2	This designation denotes strong credit quality. Good protection is afforded by the strong short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.
VMIG 3	This designation denotes acceptable credit quality. Adequate protection is afforded by the satisfactory short-term credit strength of the liquidity provider and structural and legal protections that ensure the timely payment of purchase price upon demand.
SG	This designation denotes speculative-grade credit quality. Demand features rated in this category may be supported by a liquidity provider that does not have an investment grade short-term rating or may lack the structural and/or legal protections necessary to ensure the timely payment of purchase price upon demand.

Description of S&P Global Ratings (“S&P”), a Division of S&P Global Inc., Issue Credit Ratings

A S&P issue credit rating is a forward-looking opinion about the creditworthiness of an obligor with respect to a specific financial obligation, a specific class of financial obligations, or a specific financial program (including ratings on medium-term note programs and commercial paper programs). It takes into consideration the creditworthiness of guarantors, insurers, or other forms of credit enhancement on the obligation and takes into account the currency in which the obligation is denominated. The opinion reflects S&P’s view of the obligor’s capacity and willingness to meet its financial commitments as they come due, and may assess terms, such as collateral security and subordination, which could affect ultimate payment in the event of default.

Issue credit ratings can be either long-term or short-term. Short-term ratings are generally assigned to those obligations considered short-term in the relevant market. In the U.S., for example, that means obligations with an original maturity of no more than 365 days — including commercial paper. Short-term ratings are also used to indicate the creditworthiness of an obligor with respect to put features on long-term obligations. Medium-term notes are assigned long-term ratings.

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Issue credit ratings are based, in varying degrees, on S&P’s analysis of the following considerations:

• Likelihood of payment — capacity and willingness of the obligor to meet its financial commitment on an obligation in accordance with the terms of the obligation;

• Nature of and provisions of the obligation, and the promise we impute;

• Protection afforded by, and relative position of, the obligation in the event of bankruptcy, reorganization, or other arrangement under the laws of bankruptcy and other laws affecting creditors’ rights.

Long-Term Issue Credit Ratings*

AAA	An obligation rated ‘AAA’ has the highest rating assigned by S&P. The obligor’s capacity to meet its financial commitment on the obligation is extremely strong.
AA	An obligation rated ‘AA’ differs from the highest-rated obligations only to a small degree. The obligor’s capacity to meet its financial commitment on the obligation is very strong.
A	An obligation rated ‘A’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher-rated categories. However, the obligor’s capacity to meet its financial commitment on the obligation is still strong.
BBB	An obligation rated ‘BBB’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.
BB; B; CCC; CC; and C	Obligations rated ‘BB’, ‘B’, ‘CCC’, ‘CC’, and ‘C’ are regarded as having significant speculative characteristics. ‘BB’ indicates the least degree of speculation and ‘C’ the highest. While such obligations will likely have some quality and protective characteristics, these may be outweighed by large uncertainties or major exposures to adverse conditions.
BB	An obligation rated ‘BB’ is less vulnerable to nonpayment than other speculative issues. However, it faces major ongoing uncertainties or exposure to adverse business, financial, or economic conditions, which could lead to the obligor’s inadequate capacity to meet its financial commitment on the obligation.
B	An obligation rated ‘B’ is more vulnerable to nonpayment than obligations rated ‘BB’, but the obligor currently has the capacity to meet its financial commitment on the obligation. Adverse business, financial, or economic conditions will likely impair the obligor’s capacity or willingness to meet its financial commitment on the obligation.
CCC	An obligation rated ‘CCC’ is currently vulnerable to nonpayment, and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation. In the event of adverse business, financial, or economic conditions, the obligor is not likely to have the capacity to meet its financial commitment on the obligation.
CC	An obligation rated ‘CC’ is currently highly vulnerable to nonpayment. The ‘CC’ rating is used when a default has not yet occurred, but S&P expects default to be a virtual certainty, regardless of the anticipated time to default.
C	An obligation rated ‘C’ is currently highly vulnerable to nonpayment, and the obligation is expected to have lower relative seniority or lower ultimate recovery compared to obligations that are rated higher.
D	An obligation rated ‘D’ is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D’ rating category is used when payments on an obligation are not made on the date due, unless S&P believes that such payments will be made within five business days in the absence of a stated grace period or within the earlier of the stated grace period or 30 calendar days. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation’s rating is lowered to ‘D’ if it is subject to a distressed exchange offer.
NR	This indicates that no rating has been requested, or that there is insufficient information on which to base a rating, or that S&P does not rate a particular obligation as a matter of policy.

* The ratings from ‘AA’ to ‘CCC’ may be modified by the addition of a plus (+) or minus (-) sign to show relative standing within the major rating categories.

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Short-Term Issue Credit Ratings

A-1	A short-term obligation rated ‘A-1’ is rated in the highest category by S&P. The obligor’s capacity to meet its financial commitment on the obligation is strong. Within this category, certain obligations are designated with a plus sign (+). This indicates that the obligor’s capacity to meet its financial commitment on these obligations is extremely strong.
A-2	A short-term obligation rated ‘A-2’ is somewhat more susceptible to the adverse effects of changes in circumstances and economic conditions than obligations in higher rating categories. However, the obligor’s capacity to meet its financial commitment on the obligation is satisfactory.
A-3	A short-term obligation rated ‘A-3’ exhibits adequate protection parameters. However, adverse economic conditions or changing circumstances are more likely to lead to a weakened capacity of the obligor to meet its financial commitment on the obligation.
B	A short-term obligation rated ‘B’ is regarded as vulnerable and has significant speculative characteristics. The obligor currently has the capacity to meet its financial commitments; however, it faces major ongoing uncertainties which could lead to the obligor’s inadequate capacity to meet its financial commitments.
C	A short-term obligation rated ‘C’ is currently vulnerable to nonpayment and is dependent upon favorable business, financial, and economic conditions for the obligor to meet its financial commitment on the obligation.
D	A short-term obligation rated ‘D’ is in default or in breach of an imputed promise. For non-hybrid capital instruments, the ‘D’ rating category is used when payments on an obligation are not made on the date due, unless S&P believes that such payments will be made within any stated grace period. However, any stated grace period longer than five business days will be treated as five business days. The ‘D’ rating also will be used upon the filing of a bankruptcy petition or the taking of a similar action and where default on an obligation is a virtual certainty, for example due to automatic stay provisions. An obligation’s rating is lowered to ‘D’ if it is subject to a distressed exchange offer.

Description of S&P’s Municipal Short-Term Note Ratings

A S&P U.S. municipal note rating reflects S&P’s opinion about the liquidity factors and market access risks unique to the notes. Notes due in three years or less will likely receive a note rating. Notes with an original maturity of more than three years will most likely receive a long-term debt rating. In determining which type of rating, if any, to assign, S&P’s analysis will review the following considerations:

• Amortization schedule — the larger the final maturity relative to other maturities, the more likely it will be treated as a note; and

• Source of payment — the more dependent the issue is on the market for its refinancing, the more likely it will be treated as a note.

S&P’s municipal short-term note rating symbols are as follows:

SP-1	Strong capacity to pay principal and interest. An issue determined to possess a very strong capacity to pay debt service is given a plus (+) designation.
SP-2	Satisfactory capacity to pay principal and interest, with some vulnerability to adverse financial and economic changes over the term of the notes.
SP-3	Speculative capacity to pay principal and interest.

Description of Fitch Ratings’ (“Fitch’s”) Credit Ratings Scales

Fitch’s credit ratings provide an opinion on the relative ability of an entity to meet financial commitments, such as interest, preferred dividends, repayment of principal, insurance claims or counterparty obligations. Credit ratings are used by investors as indications of the likelihood of receiving the money owed to them in accordance with the terms on which they invested.

Fitch’s credit ratings do not directly address any risk other than credit risk. In particular, ratings do not deal with the risk of a market value loss on a rated security due to changes in interest rates, liquidity and other market considerations. However, in terms

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of payment obligation on the rated liability, market risk may be considered to the extent that it influences the ability of an issuer to pay upon a commitment. Ratings nonetheless do not reflect market risk to the extent that they influence the size or other conditionality of the obligation to pay upon a commitment (for example, in the case of index-linked bonds).

In the default components of ratings assigned to individual obligations or instruments, the agency typically rates to the likelihood of non-payment or default in accordance with the terms of that instrument’s documentation. In limited cases, Fitch may include additional considerations (i.e., rate to a higher or lower standard than that implied in the obligation’s documentation). In such cases, the agency will make clear the assumptions underlying the agency’s opinion in the accompanying rating commentary.

The terms “investment grade” and “speculative grade” have established themselves over time as shorthand to describe the categories ‘AAA’ to ‘BBB’ (investment grade) and ‘BB’ to ‘D’ (speculative grade). The terms “investment grade” and “speculative grade” are market conventions, and do not imply any recommendation or endorsement of a specific security for investment purposes. “Investment grade” categories indicate relatively low to moderate credit risk, while ratings in the “speculative” categories either signal a higher level of credit risk or that a default has already occurred.

A designation of Not Rated or NR is used to denote securities not rated by Fitch where Fitch has rated some, but not all, securities comprising an issuance capital structure.

Description of Fitch’s Long-Term Corporate Finance Obligations Rating Scales

Fitch long-term obligations rating scales are as follows:

AAA	Highest credit quality. ‘AAA’ ratings denote the lowest expectation of credit risk. They are assigned only in cases of exceptionally strong capacity for payment of financial commitments. This capacity is highly unlikely to be adversely affected by foreseeable events.
AA	Very high credit quality. ‘AA’ ratings denote expectations of very low credit risk. They indicate very strong capacity for payment of financial commitments. This capacity is not significantly vulnerable to foreseeable events.
A	High credit quality. ‘A’ ratings denote expectations of low credit risk. The capacity for payment of financial commitments is considered strong. This capacity may, nevertheless, be more vulnerable to adverse business or economic conditions than is the case for higher ratings.
BBB	Good credit quality. ‘BBB’ ratings indicate that expectations of credit risk are currently low. The capacity for payment of financial commitments is considered adequate but adverse business or economic conditions are more likely to impair this capacity.
BB	Speculative. ‘BB’ ratings indicate an elevated vulnerability to credit risk, particularly in the event of adverse changes in business or economic conditions over time; however, business or financial alternatives may be available to allow financial commitments to be met.
B	Highlyspeculative. ‘B’ ratings indicate that material credit risk is present.
CCC	Substantialcredit risk. ‘CCC’ ratings indicate that substantial credit risk is present.
CC	Very  high levels of credit risk. ‘CC’ ratings indicate very high levels of credit risk.
C	Exceptionallyhigh levels of credit risk. ‘C’ indicates exceptionally high levels of credit risk.

Defaulted obligations typically are not assigned ‘RD’ or ‘D’ ratings, but are instead rated in the ‘B’ to ‘C’ rating categories, depending upon their recovery prospects and other relevant characteristics. This approach better aligns obligations that have comparable overall expected loss but varying vulnerability to default and loss.

Notes: The modifiers “+” or “-” may be appended to a rating to denote relative status within major rating categories. Such suffixes are not added to the ‘AAA’ obligation rating category, or to corporate finance obligation ratings in the categories below ‘CCC’.

The subscript ‘emr’ is appended to a rating to denote embedded market risk which is beyond the scope of the rating. The designation is intended to make clear that the rating solely addresses the counterparty risk of the issuing bank. It is not meant to indicate any limitation in the analysis of the counterparty risk, which in all other respects follows published Fitch criteria for analyzing the issuing financial institution. Fitch does not rate these instruments where the principal is to any degree subject to market risk.

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Description of Fitch’s Short-Term Ratings

A short-term issuer or obligation rating is based in all cases on the short-term vulnerability to default of the rated entity or security stream and relates to the capacity to meet financial obligations in accordance with the documentation governing the relevant obligation. Short-Term Ratings are assigned to obligations whose initial maturity is viewed as “short term” based on market convention. Typically, this means up to 13 months for corporate, sovereign, and structured obligations and up to 36 months for obligations in U.S. public finance markets.

Fitch short-term ratings are as follows:

F1	Highest short-term credit quality. Indicates the strongest intrinsic capacity for timely payment of financial commitments; may have an added “+” to denote any exceptionally strong credit feature.
F2	Good short-term credit quality. Good intrinsic capacity for timely payment of financial commitments.
F3	Fair short-term credit quality. The intrinsic capacity for timely payment of financial commitments is adequate.
B	Speculative short-term credit quality. Minimal capacity for timely payment of financial commitments, plus heightened vulnerability to near term adverse changes in financial and economic conditions.
C	High short-term default risk. Default is a real possibility.
RD	Restricted default. Indicates an entity that has defaulted on one or more of its financial commitments, although it continues to meet other financial obligations. Typically applicable to entity ratings only.
D	Default. Indicates a broad-based default event for an entity, or the default of a short-term obligation.

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APPENDIX B

BlackRock U.S. Registered Funds

iShares by BlackRock

Open-End Fund Proxy Voting Policy

Procedures Governing Delegation of Proxy Voting to Fund Adviser

July 1, 2017

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The Boards of Trustees/Directors (“Directors”) of open-end funds advised by BlackRock Fund Advisors or BlackRock Advisors, LLC (“BlackRock”) (the “Funds”), have the responsibility for the oversight of voting proxies relating to portfolio securities of the Funds, and have determined that it is in the best interests of the Funds and their shareholders to delegate the responsibility to vote proxies to BlackRock, subject to the principles outlined in this Policy, as part of BlackRock’s authority to manage, acquire and dispose of account assets, all as contemplated by the Funds’ respective investment management agreements.

BlackRock has adopted guidelines and procedures (together and as from time to time amended, the “BlackRock Proxy Voting Guidelines”) governing proxy voting by accounts managed by BlackRock.

BlackRock will cast votes on behalf of each of the Funds on specific proxy issues in respect of securities held by each such Fund (or may refrain from voting) in accordance with the BlackRock Proxy Voting Guidelines.

BlackRock will report on an annual basis to the Directors on (1) all proxy votes that BlackRock has made on behalf of the Funds in the preceding year together with a representation that all votes were in accordance with the BlackRock Proxy Voting Guidelines¹, and (2) any changes to the BlackRock Proxy Voting Guidelines that have not previously been reported.

^©2017 BlackRock

¹  iShares MSCI All Peru Capped ETF and the Social Index Funds, as defined in Appendix A of the Proxy Voting Policy for Social Index Funds have separate Fund Proxy Voting Policies.

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Global corporate governance & engagement principles

June 2014

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Contents
Introduction to BlackRock	B-5
Philosophy on corporate governance	B-5
Corporate governance, engagement and voting	B-6
— Boards and directors	B-6
— Auditors and audit-related issues	B-7
— Capital structure, mergers, asset sales and other special transactions	B-8
— Remuneration and benefits	B-8
— Social, ethical, and environmental issues	B-9
— General corporate governance matters	B-9
BlackRock’s oversight of its corporate governance activities	B-9
— Oversight	B-9
— Vote execution	B-10
— Conflicts management	B-11
— Voting guidelines	B-12
— Reporting	B-12

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INTRODUCTION TO BLACKROCK

BlackRock is the world’s preeminent asset management firm and a premier provider of global investment management, risk management and advisory services to institutional and individual clients around the world. BlackRock offers a wide range of investment strategies and product structures to meet clients’ needs, including individual and institutional separate accounts, mutual funds, closed-end funds, and other pooled investment vehicles and the industry-leading iShares exchange traded funds. Through BlackRock Solutions^®, we offer risk management, strategic advisory and enterprise investment system services to a broad base of clients.

PHILOSOPHY ON CORPORATE GOVERNANCE

BlackRock’s corporate governance program is focused on protecting and enhancing the economic value of the companies in which it invests on behalf of clients. We do this through engagement with boards and management of investee companies and, for those clients who have given us authority, through voting at shareholder meetings.

We believe that there are certain fundamental rights attached to share ownership. Companies and their boards should be accountable to shareholders and structured with appropriate checks and balances to ensure that they operate in shareholders’ interests. Effective voting rights are central to the rights of ownership and there should be one vote for one share. Shareholders should have the right to elect, remove and nominate directors, approve the appointment of the auditor and to amend the corporate charter or by-laws. Shareholders should be able to vote on matters that are material to the protection of their investment including but not limited to changes to the purpose of the business, dilution levels and pre-emptive rights, the distribution of income and the capital structure. In order to exercise these rights effectively, we believe shareholders have the right to sufficient and timely information to be able to take an informed view of the proposals, and of the performance of the company and management.

Our focus is on the board of directors, as the agent of shareholders, which should set the company’s strategic aims within a framework of prudent and effective controls which enables risk to be assessed and managed. The board should provide direction and leadership to the management and oversee management’s performance. Our starting position is to be supportive of boards in their oversight efforts on our behalf and we would generally expect to support the items of business they put to a vote at shareholder meetings. Votes cast against or withheld from resolutions proposed by the board are a signal that we are concerned that the directors or management have either not acted in the interests of shareholders or have not responded adequately to shareholder concerns regarding strategy or performance.

These principles set out our approach to engaging with companies, provide guidance on our position on corporate governance and outline how our views might be reflected in our voting decisions. Corporate governance practices vary internationally and our expectations in relation to individual companies are based on the legal and regulatory framework of each market. However, as noted above, we do believe that there are some overarching principles of corporate governance that apply globally. We assess voting matters on a case-by-case basis and in light of each company’s unique circumstances. We are interested to understand from the company’s reporting its approach to corporate governance, particularly where it is different from the usual market practice, and how it benefits shareholders.

BlackRock also believes that shareholders have responsibilities in relation to monitoring and providing feedback to companies, sometimes known as stewardship. These ownership responsibilities include, in our view, engaging with management or board members on corporate governance matters, voting proxies in the best long-term economic interests of shareholders and engaging with regulatory bodies to ensure a sound policy framework consistent with promoting long-term shareholder value creation. Institutional shareholders also have responsibilities to their clients to have appropriate resources and oversight structures. Our own approach to oversight in relation to our corporate governance activities is set out in the section below titled “BlackRock’s oversight of its corporate governance activities”.

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CORPORATE GOVERNANCE, ENGAGEMENT AND VOTING

We recognize that accepted standards of corporate governance differ between markets but we believe that there are sufficient common threads globally to identify an overarching set of principles. The primary objective of our corporate governance activities is the protection and enhancement of the value of our clients’ investments in public corporations. Thus, these principles focus on practices and structures that we consider to be supportive of long-term value creation. We discuss below the principles under six key themes. In our regional and market-specific voting guidelines we explain how these principles inform our voting decisions in relation to specific resolutions that may appear on the agenda of a shareholder meeting in the relevant market.

The six key themes are:

• Boards and directors

• Auditors and audit-related issues

• Capital structure, mergers, asset sales and other special transactions

• Remuneration and benefits

• Social, ethical and environmental issues

• General corporate governance matters

At a minimum we would expect companies to observe the accepted corporate governance standard in their domestic market or to explain why doing so is not in the interests of shareholders. Where company reporting and disclosure is inadequate or the approach taken is inconsistent with our view of what is in the best interests of shareholders, we will engage with the company and/or use our vote to encourage a change in practice. In making voting decisions, we take into account research from proxy advisors, other internal and external research, information published by the company or provided through engagement and the views of our equity portfolio managers.

BlackRock views engagement as an important activity; engagement provides BlackRock with the opportunity to improve our understanding of investee companies and their governance structures, so that our voting decisions may be better informed. Engagement also allows us to share our philosophy and approach to investment and corporate governance with companies to enhance their understanding of our objectives. There are a range of approaches we may take in engaging companies depending on the nature of the issue under consideration, the company and the market.

Boards and directors

The performance of the board is critical to the economic success of the company and to the protection of shareholders’ interests. Board members serve as agents of shareholders in overseeing the strategic direction and operation of the company. For this reason, BlackRock focuses on directors in many of its engagements and sees the election of directors as one of its most important responsibilities in the proxy voting context.

We expect the board of directors to promote and protect shareholder interests by:

• establishing an appropriate corporate governance structure;

• supporting and overseeing management in setting strategy;

• ensuring the integrity of financial statements;

• making decisions regarding mergers, acquisitions and disposals;

• establishing appropriate executive compensation structures; and

• addressing business issues including social, ethical and environmental issues when they have the potential to materially impact company reputation and performance.

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There should be clear definitions of the role of the board, the sub-committees of the board and the senior management such that the responsibilities of each are well understood and accepted. Companies should report publicly the approach taken to governance (including in relation to board structure) and why this approach is in the interest of shareholders. We will engage with the appropriate directors where we have concerns about the performance of the board or the company, the broad strategy of the company or the performance of individual board members. Concerns about directors may include their role on the board of a different company where that board has performed poorly and failed to protect shareholder interests.

BlackRock believes that directors should stand for re-election on a regular basis. We assess directors nominated for election or re-election in the context of the composition of the board as a whole. There should be detailed disclosure of the relevant credentials of the individual directors in order that shareholders can assess the caliber of an individual nominee. We expect there to be a sufficient number of independent directors on the board to ensure the protection of the interests of all shareholders. Common impediments to independence may include but are not limited to:

• current employment at the company or a subsidiary;

• former employment within the past several years as an executive of the company;

• providing substantial professional services to the company and/or members of the company’s management;

• having had a substantial business relationship in the past three years;

• having, or representing a shareholder with, a substantial shareholding in the company;

• being an immediate family member of any of the aforementioned; and

• interlocking directorships.

BlackRock believes that the operation of the board is enhanced when there is a clearly independent, senior non-executive director to lead it. Where the chairman is also the CEO or is otherwise not independent the company should have an independent lead director. The role of this director is to enhance the effectiveness of the independent members of the board through shaping the agenda, ensuring adequate information is provided to the board and encouraging independent participation in board deliberations. The lead independent board director should be available to shareholders if they have concerns that they wish to discuss.

To ensure that the board remains effective, regular reviews of board performance should be carried out and assessments made of gaps in skills or experience amongst the members. BlackRock believes it is beneficial for new directors to be brought onto the board periodically to refresh the group’s thinking and to ensure both continuity and adequate succession planning. In identifying potential candidates, boards should take into consideration the diversity of experience and expertise of the current directors and how that might be augmented by incoming directors. We believe that directors are in the best position to assess the optimal size for the board, but we would be concerned if a board seemed too small to have an appropriate balance of directors or too large to be effective.

There are matters for which the board has responsibility that may involve a conflict of interest for executives or for affiliated directors. BlackRock believes that shareholders’ interests are best served when the independent members of the board form a sub-committee to deal with such matters. In many markets, these sub-committees of the board specialize in audit, director nominations and compensation matters. An ad hoc committee might also be formed to decide on a special transaction, particularly one with a related party.

Auditors and audit-related issues

BlackRock recognizes the critical importance of financial statements which should provide a complete and accurate picture of a company’s financial condition. We will hold the members of the audit committee or equivalent responsible for overseeing the management of the audit function. We take particular note of cases involving significant financial restatements or ad hoc notifications of material financial weakness.

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The integrity of financial statements depends on the auditor being free of any impediments to being an effective check on management. To that end, we believe it is important that auditors are, and are seen to be, independent. Where the audit firm provides services to the company in addition to the audit, the fees earned should be disclosed and explained. Audit committees should also have in place a procedure for assuring annually the independence of the auditor.

Capital structure, mergers, asset sales and other special transactions

The capital structure of a company is critical to its owners, the shareholders, as it impacts the value of their investment and the priority of their interest in the company relative to that of other equity or debt investors. Pre-emption rights are a key protection for shareholders against the dilution of their interests.

In assessing mergers, asset sales or other special transactions, BlackRock’s primary consideration is the long-term economic interests of shareholders. Boards proposing a transaction need to clearly explain the economic and strategic rationale behind it. We will review a proposed transaction to determine the degree to which it enhances long-term shareholder value. We would prefer that proposed transactions have the unanimous support of the board and have been negotiated at arm’s length. We may seek reassurance from the board that executive and/or board members’ financial interests in a given transaction have not affected their ability to place shareholders’ interests before their own. Where the transaction involves related parties, we would expect the recommendation to support it to come from the independent directors and would prefer only non-conflicted shareholders to vote on the proposal.

BlackRock believes that shareholders have a right to dispose of company shares in the open market without unnecessary restriction. In our view, corporate mechanisms designed to limit shareholders’ ability to sell their shares are contrary to basic property rights. Such mechanisms can serve to protect and entrench interests other than those of the shareholders. We believe that shareholders are broadly capable of making decisions in their own best interests. We would expect any so-called ‘shareholder rights plans’ being proposed by a board to be subject to shareholder approval on introduction and periodically thereafter for continuation.

Remuneration and benefits

BlackRock expects a company’s board of directors to put in place a compensation structure that incentivizes and rewards executives appropriately and is aligned with shareholder interests, particularly long-term shareholder returns. We would expect the compensation committee to take into account the specific circumstances of the company and the key individuals the board is trying to incentivize. We encourage companies to ensure that their compensation packages incorporate appropriate and challenging performance conditions consistent with corporate strategy and market practice. We use third party research, in addition to our own analysis, to evaluate existing and proposed compensation structures. We hold members of the compensation committee or equivalent accountable for poor compensation practices or structures.

BlackRock believes that there should be a clear link between variable pay and company performance as reflected in returns to shareholders. We are not supportive of one-off or special bonuses unrelated to company or individual performance. We support incentive plans that pay out rewards earned over multiple and extended time periods. We believe consideration should be given to building claw back provisions into incentive plans such that executives would be required to repay rewards where they were not justified by actual performance. Compensation committees should guard against contractual arrangements that would entitle executives to material compensation for early termination of their contract. Finally, pension contributions should be reasonable in light of market practice.

Outside directors should be compensated in a manner that does not risk compromising their independence or aligning their interests too closely with those of the management, whom they are charged with overseeing.

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Social, ethical, and environmental issues

Our fiduciary duty to clients is to protect and enhance their economic interest in the companies in which we invest on their behalf. It is within this context that we undertake our corporate governance activities. We believe that well-managed companies will deal effectively with the social, ethical and environmental (“SEE”) aspects of their businesses.

BlackRock expects companies to identify and report on the material, business-specific SEE risks and opportunities and to explain how these are managed. This explanation should make clear how the approach taken by the company best serves the interests of shareholders and protects and enhances the long-term economic value of the company. The key performance indicators in relation to SEE matters should also be disclosed and performance against them discussed, along with any peer group benchmarking and verification processes in place. This helps shareholders assess how well management is dealing with the SEE aspects of the business. Any global standards adopted should also be disclosed and discussed in this context.

We may vote against the election of directors where we have concerns that a company might not be dealing with SEE issues appropriately. Sometimes we may reflect such concerns by supporting a shareholder proposal on the issue, where there seems to be either a significant potential threat or realized harm to shareholders’ interests caused by poor management of SEE matters. In deciding our course of action, we will assess whether the company has already taken sufficient steps to address the concern and whether there is a clear and material economic disadvantage to the company if the issue is not addressed.

More commonly, given that these are often not voting issues, we will engage directly with the board or management. The trigger for engagement on a particular SEE concern is our assessment that there is potential for material economic ramifications for shareholders.

We do not see it as our role to make social, ethical or political judgments on behalf of clients. We expect investee companies to comply, at a minimum, with the laws and regulations of the jurisdictions in which they operate. They should explain how they manage situations where such laws or regulations are contradictory or ambiguous.

General corporate governance matters

BlackRock believes that shareholders have a right to timely and detailed information on the financial performance and viability of the companies in which they invest. In addition, companies should also publish information on the governance structures in place and the rights of shareholders to influence these. The reporting and disclosure provided by companies helps shareholders assess whether the economic interests of shareholders have been protected and the quality of the board’s oversight of management. BlackRock believes shareholders should have the right to vote on key corporate governance matters, including on changes to governance mechanisms, to submit proposals to the shareholders’ meeting and to call special meetings of shareholders.

BLACKROCK’S OVERSIGHT OF ITS CORPORATE GOVERNANCE ACTIVITIES

Oversight

BlackRock holds itself to a very high standard in its corporate governance activities, including in relation to executing proxy votes. This function is executed by a team of dedicated BlackRock employees without sales responsibilities (the “Corporate Governance Group”), and which is considered an investment function. BlackRock maintains three regional oversight committees (“Corporate Governance Committees”) for the Americas, Europe, the Middle East and Africa (EMEA) and Asia-Pacific, consisting of senior BlackRock investment professionals. All of the regional Corporate Governance Committees report to a Global Corporate Governance Oversight Committee, which is a risk-focused committee composed of senior representatives of the active and index equity investment businesses, the Deputy General Counsel, the Global Executive Committee member to whom the Corporate Governance Group reports and the head of the Corporate Governance Group. The Corporate Governance Committees review and approve amendments to their

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respective proxy voting guidelines (“Guidelines”) and grant authority to the Global Head of Corporate Governance (“Global Head”), a dedicated BlackRock employee without sales responsibilities, to vote in accordance with the Guidelines. The Global Head leads the Corporate Governance Group to carry out engagement, voting and vote operations in a manner consistent with the relevant Corporate Governance Committee’s mandate. The Corporate Governance Group engages companies in conjunction with the portfolio managers in discussions of significant governance issues, conducts research on corporate governance issues and participates in industry discussions to keep abreast of the field of corporate governance. The Corporate Governance Group, or vendors overseen by the Corporate Governance Group, also monitor upcoming proxy votes, execute proxy votes and maintain records of votes cast. The Corporate Governance Group may refer complicated or particularly controversial matters or discussions to the appropriate investors and/or regional Corporate Governance Committees for their review, discussion and guidance prior to making a voting decision.

BlackRock’s Equity Policy Oversight Committee (EPOC) is informed of certain aspects of the work of the Global Corporate Governance Oversight Committee and the Corporate Governance Group.

Vote execution

BlackRock carefully considers proxies submitted to funds and other fiduciary accounts (“Funds”) for which it has voting authority. BlackRock votes (or refrains from voting) proxies for each Fund for which it has voting authority based on BlackRock’s evaluation of the best long-term economic interests of shareholders, in the exercise of its independent business judgment, and without regard to the relationship of the issuer of the proxy (or any dissident shareholder) to the Fund, the Fund’s affiliates (if any), BlackRock or BlackRock’s affiliates.

When exercising voting rights, BlackRock will normally vote on specific proxy issues in accordance with its Guidelines for the relevant market. The Guidelines are reviewed regularly and are amended consistent with changes in the local market practice, as developments in corporate governance occur, or as otherwise deemed advisable by BlackRock’s Corporate Governance Committees. The Corporate Governance Committees may, in the exercise of their business judgment, conclude that the Guidelines do not cover the specific matter upon which a proxy vote is requested or that an exception to the Guidelines would be in the best long-term economic interests of BlackRock’s clients.

In the uncommon circumstance of there being a vote with respect to fixed income securities or the securities of privately held issuers the decision generally will be made by a Fund’s portfolio managers and/or the Corporate Governance Group based on their assessment of the particular transactions or other matters at issue.

In certain markets, proxy voting involves logistical issues which can affect BlackRock’s ability to vote such proxies, as well as the desirability of voting such proxies. These issues include but are not limited to: (i) untimely notice of shareholder meetings; (ii) restrictions on a foreigner’s ability to exercise votes; (iii) requirements to vote proxies in person; (iv) “share-blocking” (requirements that investors who exercise their voting rights surrender the right to dispose of their holdings for some specified period in proximity to the shareholder meeting); (v) potential difficulties in translating the proxy; and (vi) requirements to provide local agents with unrestricted powers of attorney to facilitate voting instructions. We are not supportive of impediments to the exercise of voting rights such as shareblocking or overly burdensome administrative requirements.

As a consequence, BlackRock votes proxies in these markets only on a “best-efforts” basis. In addition, the Corporate Governance Committees may determine that it is generally in the best interests of BlackRock clients not to vote proxies of companies in certain countries if the committee determines that the costs (including but not limited to opportunity costs associated with shareblocking constraints) associated with exercising a vote are expected to outweigh the benefit the client would derive by voting on the issuer’s proposal.

While it is expected that BlackRock, as a fiduciary, will generally seek to vote proxies over which BlackRock exercises voting authority in a uniform manner for all BlackRock clients, the relevant Corporate Governance Committee, in conjunction with the portfolio manager of an account, may determine that the specific

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circumstances of such an account require that such account’s proxies be voted differently due to such account’s investment objective or other factors that differentiate it from other accounts. In addition, BlackRock believes portfolio managers may from time to time legitimately reach differing but equally valid views, as fiduciaries for their funds and the client assets in those Funds, on how best to maximize economic value in respect of a particular investment. Accordingly, portfolio managers retain full discretion to vote the shares in the Funds they manage based on their analysis of the economic impact of a particular ballot item.

Conflicts management

BlackRock maintains policies and procedures that are designed to prevent undue influence on BlackRock’s proxy voting activity that might stem from any relationship between the issuer of a proxy (or any dissident shareholder) and BlackRock, BlackRock’s affiliates, a Fund or a Fund’s affiliates. Some of the steps BlackRock has taken to prevent conflicts include, but are not limited to:

• BlackRock has adopted a proxy voting oversight structure whereby the Corporate Governance Committees oversee the voting decisions and other activities of the Corporate Governance Group, and particularly its activities with respect to voting in the relevant region of each Corporate Governance Committee’s jurisdiction.

• The Corporate Governance Committees have adopted Guidelines for each region, which set forth the firm’s views with respect to certain corporate governance and other issues that typically arise in the proxy voting context. The Corporate Governance Committees receive periodic reports regarding the specific votes cast by the Corporate Governance Group and regular updates on material process issues, procedural changes and other matters of concern to the Corporate Governance Committees.

• BlackRock’s Global Corporate Governance Oversight Committee oversees the Global Head, the Corporate Governance Group and the Corporate Governance Committees. The Global Corporate Governance Oversight Committee conducts a review, at least annually, of the proxy voting process to ensure compliance with BlackRock’s risk policies and procedures.

• BlackRock maintains a reporting structure that separates the Global Head and Corporate Governance Group from employees with sales responsibilities. In addition, BlackRock maintains procedures intended to ensure that all engagements with corporate issuers or dissident shareholders are managed consistently and without regard to BlackRock’s relationship with the issuer of the proxy or dissident shareholder. Within the normal course of business, the Global Head or Corporate Governance Group may engage directly with BlackRock clients, and with employees with sales responsibilities, in discussions regarding general corporate governance policy matters, and to otherwise ensure that proxy-related client service levels are met. The Global Head or Corporate Governance Group does not discuss any specific voting matter with a client prior to the disclosure of the vote decision to all applicable clients after the shareholder meeting has taken place, except if the client is acting in the capacity as issuer of the proxy or dissident shareholder and is engaging through the established procedures independent of the client relationship.

• In certain instances, BlackRock may determine to engage an independent fiduciary to vote proxies as a further safeguard to avoid potential conflicts of interest or as otherwise required by applicable law. The independent fiduciary may either vote such proxies or provide BlackRock with instructions as to how to vote such proxies. In the latter case, BlackRock votes the proxy in accordance with the independent fiduciary’s determination. Use of an independent fiduciary has been adopted for voting the proxies related to any company that is affiliated with BlackRock or any company that includes BlackRock employees on its board of directors.

With regard to the relationship between securities lending and proxy voting, BlackRock’s approach is driven by our clients’ economic interests. The evaluation of the economic desirability of recalling loans involves

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balancing the revenue producing value of loans against the likely economic value of casting votes. Based on our evaluation of this relationship, we believe that generally the likely economic value of casting most votes is less than the securities lending income, either because the votes will not have significant economic consequences or because the outcome of the vote would not be affected by BlackRock recalling loaned securities in order to ensure they are voted. Periodically, BlackRock analyzes the process and benefits of voting proxies for securities on loan, and will consider whether any modification of its proxy voting policies or procedures is necessary in light of future conditions. In addition, BlackRock may in its discretion determine that the value of voting outweighs the cost of recalling shares, and thus recall shares to vote in that instance.

Voting guidelines

The issue-specific voting Guidelines published for each region/country in which we vote are intended to summarize BlackRock’s general philosophy and approach to issues that may commonly arise in the proxy voting context in each market where we invest. These Guidelines are not intended to be exhaustive. BlackRock applies the Guidelines on a case-by-case basis, in the context of the individual circumstances of each company and the specific issue under review.

As such, these Guidelines do not provide a guide to how BlackRock will vote in every instance. Rather, they share our view about corporate governance issues generally, and provide insight into how we typically approach issues that commonly arise on corporate ballots.

Reporting

We report our proxy voting activity directly to clients and publically as required. In addition, we publish for clients a more detailed discussion of our corporate governance activities, including engagement with companies and with other relevant parties.

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SAI-HYM-K-0118