Summary Prospectus    January 1, 2020 American Century Investments® California High-Yield Municipal Fund
Investor Class: BCHYX I Class: BCHIX	Y Class: ACYHX A Class: CAYAX	C Class: CAYCX

Before you invest, you may want to review the fund’s prospectus, which contains more information about the fund and its risks. You can find the fund’s prospectus, reports to shareholders, and other information about the fund online at the web addresses listed below. You can also get this information at no cost by calling or sending an email request. The fund’s prospectus and other information are also available from financial intermediaries (such as banks and broker-dealers) through which shares of the fund may be purchased or sold. Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the fund’s shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the fund or from your financial intermediary, such as a broker-dealer or bank. Instead, the reports will be made available on a website, and you will be notified by mail each time a report is posted and provided with a website link to access the report. If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the fund or your financial intermediary electronically by calling or sending an email request. You may elect to receive all future reports in paper free of charge. You can inform the fund or your financial intermediary that you wish to continue receiving paper copies of your shareholder reports by calling or sending an email request. Your election to receive reports in paper will apply to all funds held with the fund complex/your financial intermediary.
Retail Investors americancentury.com/prospectus 1-800-345-2021 or 816-531-5575 prospectus@americancentury.com	Financial Professionals americancentury.com/fa-prospectus 1-800-345-6488 advisor_prospectus@americancentury.com
This summary prospectus incorporates by reference the fund’s prospectus and statement of additional information (SAI), each dated January 1, 2020 (as supplemented at the time you receive this summary prospectus), as well as the Report of Independent Registered Public Accounting Firm and the financial statements included in the fund’s annual report to shareholders, dated August 31, 2019. The fund’s SAI and annual report may be obtained, free of charge, in the same manner as the prospectus.

Investment Objective

The fund seeks high current income that is exempt from federal and California income taxes.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy, hold and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for A Class sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 12 of the fund’s prospectus, Appendix A of the fund’s prospectus and Sales Charges in Appendix B of the statement of additional information.

Shareholder Fees (fees paid directly from your investment)
	Investor	I	Y	A	C
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	4.50%	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase)	None	None	None	None¹	1.00%
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000)	$25	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Investor	I	Y	A	C
Management Fee	0.49%	0.29%	0.26%	0.49%	0.49%
Distribution and Service (12b-1) Fees	None	None	None	0.25%	1.00%
Other Expenses	0.01%	0.01%	0.01%	0.01%	0.01%
Total Annual Fund Operating Expenses	0.50%	0.30%	0.27%	0.75%	1.50%

¹  Purchases of $1 million or more may be subject to a contingent deferred sales charge of 1.00% if the shares are redeemed within one year of the date of the purchase.

Example

The example below is intended to help you compare the costs of investing in the fund with the costs 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, that you earn 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
Investor Class	$51	$161	$280	$629
I Class	$31	$97	$169	$381
Y Class	$28	$87	$152	$344
A Class	$523	$679	$849	$1,339
C Class	$153	$475	$819	$1,789

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 fund 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 39% of the average value of its portfolio.

Principal Investment Strategies

The fund invests in California municipal and other debt securities with an emphasis on high-yield securities. A high-yield security is one that has been rated below investment-grade, or determined by the investment advisor to be of similar quality. Under normal market conditions, the portfolio managers invest at least 80% of the fund’s net assets in municipal securities with income payments exempt from federal and California income taxes. Cities, counties and other municipalities in California and U.S. territories usually issue these securities for public projects, such as schools, roads, and water and sewer systems. Some of these investments are not necessarily exempt from the federal alternative minimum tax. 

The portfolio managers seek to invest in securities that will result in a high yield for the fund. To accomplish this, the portfolio managers buy securities that are rated below investment-grade, including so-called junk bonds and bonds that are in technical or monetary default. Issuers of these securities often have short financial histories or have questionable credit or have had and may continue to have problems making interest and principal payments. 

The portfolio managers also may buy unrated securities if they determine such securities meet the investment objectives of the fund. 

Although the fund invests primarily for income, it also employs techniques designed to realize capital appreciation. For example, the portfolio managers may select bonds with maturities and coupon rates that position the fund for potential capital appreciation for a variety of reasons, including their view on the direction of future interest-rate movements and the potential for a credit upgrade.

When determining whether to sell a security, the portfolio managers consider, among other things, current and anticipated changes in interest rates, the credit quality of a particular issuer, comparable alternatives, general market conditions and any other factor deemed relevant by the portfolio managers. 

Principal Risks 

• Credit Risk – Debt securities, even investment-grade debt securities, are subject to credit risk. Credit risk is the risk that the inability or perceived inability of the issuer to make interest and principal payments will cause the value of the securities to decrease. As a result, the fund’s share price could also decrease. Changes in the credit rating of a debt security held by the fund could have a similar effect. The fund’s investments often have high credit risk, which helps the fund pursue a higher yield than more conservatively managed bond funds.

• Below Investment-Grade Securities Risk – Issuers of lower rated, high-yield securities are more vulnerable to real or perceived economic changes (such as an economic downturn or a prolonged period of rising interest rates), political changes, or adverse developments specific to the issuer. Adverse economic, political and other developments may be more likely to cause an issuer of low-quality bonds to default on its obligation to pay interest and principal due under its securities. The fund invests a significant part of its assets in securities rated below investment-grade or that are unrated, including bonds that are in technical or monetary default. By definition, the issuers of many of these securities have had and may continue to have problems making interest and principal payments.

• Interest Rate Risk – When interest rates change, the fund’s share value will be affected. Generally, the value of debt securities and the funds that hold them decline as interest rates rise. Because the fund typically invests in intermediate-term and long-term bonds, the fund’s interest rate risk is generally higher than for funds with shorter-weighted average maturities, such as money market and short-term bond funds. A period of rising interest rates may negatively affect the fund’s performance.

• California Economic Risk – The fund will be sensitive to events that affect California’s economy. Significant political or economic developments in California will likely impact virtually all municipal securities issued in the state. Because the fund invests principally in California municipal securities, it may have a higher level of risk than funds that invest in a larger universe of securities.

• Municipal Securities Risk – Because the fund invests principally in municipal securities, it will be sensitive to events that affect municipal markets, including legislative or political changes and the financial condition of the issuers of municipal securities. The fund may have a higher level of risk than funds that invest in a larger universe of securities.

• Liquidity Risk – The fund may also be subject to liquidity risk. During periods of market turbulence or unusually low trading activity, in order to meet redemptions, it may be necessary for the fund to sell securities at prices that could have an adverse effect on the fund’s share price. Changing regulatory and market conditions, including increases in interest rates and credit spreads may adversely affect the liquidity of the fund’s investments.

• Tax Risk – Some or all of the fund’s income may be subject to the federal alternative minimum tax. There is no guarantee that all of the fund’s income will remain exempt from federal or state income taxes. Income from municipal bonds held by a fund could be declared taxable because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service or state tax authorities, or non-compliant conduct of a bond issuer. The fund may sell securities that lose their tax-exempt statuses at inopportune times, which may cause tax consequences or a decrease in the fund’s value.

• Market Risk – The value of securities owned by the fund may go up and down, sometimes rapidly or unpredictably.

• Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency. 

Fund Performance

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Investor Class shares. The table shows how the fund’s average annual returns for the periods shown compared with those of a broad measure of market performance. The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, please visit americancentury.com. 

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown. 

Calendar Year Total Returns

Highest Performance Quarter (3Q 2009): 12.08%Lowest Performance Quarter (4Q 2016): -5.59%

As of September 30, 2019, the most recent calendar quarter end, the fund’s Investor Class year-to-date return was 8.86%.

Average Annual Total Returns For the calendar year ended December 31, 2018	1 year	5 years	10 years	Since Inception	Inception Date
Investor Class Return Before Taxes	0.63%	5.54%	6.98%	—	12/30/1986
Return After Taxes on Distributions	0.63%	5.54%	6.98%	—	12/30/1986
Return After Taxes on Distributions and Sale of Fund Shares	1.79%	5.18%	6.56%	—	12/30/1986
I Class Return Before Taxes	0.93%	5.75%	—	5.65%	03/01/2010
Y Class Return Before Taxes	0.85%	—	—	3.71%	04/10/2017
A Class Return Before Taxes	-4.11%	4.30%	6.22%	—	01/31/2003
C Class Return Before Taxes	-0.37%	4.47%	5.92%	—	01/31/2003
Bloomberg Barclays Municipal Bond Index    (reflects no deduction for fees, expenses and taxes)	1.28%	3.82%	4.85%	—	—
S&P Municipal Bond California 50% Investment Grade/50% High Yield Index1    (reflects no deduction for fees, expenses and taxes)	1.52%	6.54%	—	—	—

¹  Effective December 31, 2017, the fund’s investment advisor selected a different benchmark for comparison purposes. The advisor believes the S&P Municipal Bond California 50% Investment Grade/50% High Yield Index is more reflective of the fund’s strategy. Because the S&P Municipal Bond California 50% Investment Grade/50% High Yield Index total return data is first available as of December 30, 2011, returns for the Bloomberg Barclays Municipal Bond Index are also shown to cover the 10 year period.

After-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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 an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.

Portfolio Management 

Investment Advisor

American Century Investment Management, Inc. 

Portfolio Managers

Steven M. Permut, Senior Vice President and Senior Portfolio Manager, has served on teams managing fixed-income investments for American Century Investments since joining the advisor in 1987.

Joseph Gotelli, Vice President and Portfolio Manager, has served on teams managing fixed-income investments for American Century Investments since joining the advisor in 2008.

Alan Kruss, Vice President and Portfolio Manager, has served on teams managing fixed-income investments for American Century Investments since joining the advisor in 1997.

Purchase and Sale of Fund Shares 

You may purchase or redeem shares of the fund on any business day through our website at americancentury.com, in person (at one of our Investor Centers), by mail (American Century Investments, P.O. Box 419200, Kansas City, MO 64141-6200), by telephone at 1-800-345-2021 (Investor Services Representative) or 1-800-345-3533 (Business, Not-For-Profit and Employer Sponsored Retirement Plans), or through a financial intermediary. Shares may be purchased and redemption proceeds received by electronic bank transfer, by check or by wire. 

Unless otherwise specified below, the minimum initial investment amount to open an account is $5,000 (including Coverdell Education Savings Accounts). Investors opening accounts through financial intermediaries may open an account with $250 for Investor, A and C Classes, but the financial intermediaries may require their clients to meet different investment minimums. The minimum may be waived for broker-dealer sponsored wrap program accounts, fee based accounts, and accounts through bank/trust and wealth management advisory organizations.

The minimum initial investment amount for the I Class is generally $5 million ($3 million for endowments and foundations), but the minimum may be waived if you have an aggregate investment in the American Century family of funds of $10 million or more ($5 million for endowments and foundations). This includes accounts held directly with American Century and those held through a financial intermediary.

There is no minimum initial investment amount for Y Class shares.

For the Investor, A and C Classes, there is no minimum initial investment amount for certain employer-sponsored retirement plans, however, financial intermediaries or plan recordkeepers may require plans to meet different minimums. For purposes of fund minimums, employer-sponsored retirement plans do not include SEP IRAs, SIMPLE IRAs or SARSEPs. Employer-sponsored retirement plans are not eligible to invest in the I or Y Class.

There is a $50 minimum for subsequent purchases, except that there is no subsequent purchase minimum for financial intermediaries or employer-sponsored retirement plans.

Tax Information

The fund intends to distribute income that is exempt from regular federal and California income tax, however, fund distributions may be subject to capital gains tax. A portion of the fund’s distributions may be subject to federal and/or California income taxes or to the federal alternative minimum tax.

If you hold your fund shares through a tax-deferred investment plan, such as a 401(k) plan or an IRA, any distributions received from the fund may be taxable as ordinary income upon withdrawal from the tax-deferred plan, regardless of whether the distributions were tax-exempt when earned. 

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the fund through a broker-dealer or other financial intermediary (such as a bank, insurance company, plan sponsor or financial professional), the fund and its related companies may pay the intermediary for the sale of fund shares and related services for investments in all classes except the Y Class. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

^©2020 American Century Proprietary Holdings, Inc. All rights reserved.

CL-SUM-91751   2001