Schedule of Investments(unaudited) February 29, 2024 BlackRock Impact Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Municipal Bonds
Arizona — 2.2%
Arizona Industrial Development Authority, RB 5.25%, 07/01/43(a)	$	150	$	147,034
Series A, 4.00%, 02/01/50		1,000		932,049
				1,079,083
Arkansas — 3.1%
Arkansas Development Finance Authority, RB AMT, Sustainability Bonds, 5.70%, 05/01/53		100		103,357
Series A, AMT, Sustainability Bonds, 6.88%, 07/01/48(a)		300		326,681
University of Arkansas, RB, Series A, 5.00%, 04/01/47		1,000		1,090,441
				1,520,479
California — 10.1%
California Community Choice Financing Authority, RB(b)
5.00%, 05/01/54		1,440		1,548,212
Series G, 5.25%, 11/01/54		360		384,138
Series A, Sustainability Bonds, 4.00%, 10/01/52		1,500		1,504,158
California School Finance Authority, RB, 5.00%, 08/01/42(a)		125		126,370
California State Public Works Board, RB, Series D, Sustainability Bonds, 4.00%, 05/01/45		1,000		1,032,977
CSCDA Community Improvement Authority, RB, M/F Housing(a)
3.25%, 04/01/57		250		173,951
Series A-2, Sustainability Bonds, 3.00%, 02/01/57		350		236,317
				5,006,123
Colorado — 1.7%
Colorado School of Mines, RB, Series A, Sustainability Bonds, (AGM), 5.25%, 12/01/47		290		313,628
Denver City & County School District No. 1, GO, Series A, (SAW), 5.00%, 12/01/45		500		550,557
				864,185
Connecticut — 4.9%
Connecticut State Health & Educational Facilities Authority, RB, 5.25%, 07/15/48		180		194,870
State of Connecticut, GO, Series B, Sustainability Bonds, 5.00%, 01/15/42		1,000		1,112,351
University of Connecticut, RB, Series A, 5.00%, 05/01/39		1,000		1,121,138
				2,428,359
Delaware — 0.1%
Affordable Housing Opportunities Trust, RB, Series 2022 AH-01, 6.88%, 05/01/39(a)(c)		80		73,976
District of Columbia — 2.9%
District of Columbia, RB, Class A, AMT, 5.50%, 02/28/34		1,000		1,173,954
Washington Metropolitan Area Transit Authority Dedicated Revenue, RB, Series A, Sustainability Bonds, 4.13%, 07/15/47		250		250,065
				1,424,019
Florida — 6.9%
Brevard County Health Facilities Authority, Refunding RB, Series A, 4.00%, 04/01/52		1,000		947,180
Florida Development Finance Corp., RB Series A, 4.00%, 06/15/42		500		458,405

Security	Par (000)		Value
Florida (continued)
Florida Development Finance Corp., RB (continued)
Series A, 5.00%, 06/15/47	$	375	$	375,786
St Lucie County School Board, COP, Series A, (AGM), 5.00%, 07/01/48		1,500		1,640,997
				3,422,368
Georgia — 0.6%
Georgia Housing & Finance Authority, Refunding RB, S/F Housing, Series A, 4.00%, 06/01/49		325		324,212
Illinois — 5.7%
Chicago Board of Education, GO
Series A, 5.00%, 12/01/33		500		526,639
Series A, 5.00%, 12/01/47		500		513,095
Chicago Transit Authority Sales Tax Receipts Fund, Refunding RB, Series A, 2nd Lien, 5.00%, 12/01/57		1,200		1,218,861
Illinois Housing Development Authority, RB, S/F Housing, Series G, Sustainability Bonds, (FHLMC, FNMA, GNMA), 6.25%, 10/01/52		335		360,300
Illinois Housing Development Authority, Refunding RB, S/F Housing, Series H, Sustainability Bonds, (FHLMC, FNMA, GNMA), 5.75%, 10/01/53		215		229,754
				2,848,649
Kentucky — 3.1%
City of Henderson Kentucky, RB, Series A, AMT, 4.70%, 01/01/52(a)		500		482,725
Louisville/Jefferson County Metropolitan Government, RB, Series A, (AGM), 5.00%, 05/15/47		1,000		1,068,298
				1,551,023
Louisiana — 2.5%
Jefferson Parish Consolidated Sewerage District No. 1, RB, (BAM), 4.00%, 02/01/39		1,000		1,016,543
Louisiana Public Facilities Authority, RB, Series A, 6.38%, 06/01/52(a)		250		243,118
				1,259,661
Maine — 0.2%
Finance Authority of Maine, RB, AMT, Sustainability Bonds, 8.00%, 12/01/51(a)		100		78,350
Maryland — 1.5%
Maryland Economic Development Corp., RB, Class B, AMT, Sustainability Bonds, 5.25%, 06/30/47		715		731,432
Massachusetts — 5.2%
Commonwealth of Massachusetts Transportation Fund Revenue, RB, Sustainability Bonds, 5.00%, 06/01/50		1,500		1,600,380
University of Massachusetts Building Authority, RB, Series 1, 4.00%, 11/01/46		1,000		992,419
				2,592,799
Michigan — 4.9%
Ludington Area School District, GO, Series II, (BAM Q-SBLF), 4.00%, 05/01/51		1,000		902,247
Michigan Finance Authority, RB, 4.00%, 02/15/47		500		473,695
Michigan State Housing Development Authority, RB, M/F Housing, Series A, 5.10%, 10/01/53		1,000		1,043,437
				2,419,379

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Schedule of Investments(unaudited) (continued) February 29, 2024 BlackRock Impact Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Minnesota — 1.8%
Duluth Economic Development Authority, RB, Class B, 5.25%, 06/15/42	$	500	$	522,356
Minnesota Housing Finance Agency, RB, S/F Housing, Series M, Sustainability Bonds, (FHLMC, FNMA, GNMA), 6.00%, 01/01/53		340		363,235
				885,591
New Hampshire — 1.5%
New Hampshire Business Finance Authority, RB, M/F Housing, Sustainability Bonds, 4.38%, 09/20/36		734		724,249
New Jersey — 0.2%
Camden County Improvement Authority, RB, Sustainability Bonds, 6.00%, 06/15/47		115		125,779
New York — 13.2%
Build NYC Resource Corp., RB
Series A, 5.00%, 07/01/32		245		233,894
Series A, 5.13%, 07/01/33		175		179,166
Series A, 5.50%, 06/15/63(a)		250		232,038
Sustainability Bonds, 5.75%, 06/01/42(a)		250		262,238
Metropolitan Transportation Authority, Refunding RB, Series A-1, Sustainability Bonds, 5.00%, 11/15/49		1,000		1,046,964
Nassau County Local Economic Assistance Corp., RB, Series A, 5.00%, 07/01/43		1,000		1,026,717
New York City Housing Development Corp., RB, M/F Housing
Class F-1, Sustainability Bonds, 4.75%, 11/01/47		1,000		1,015,714
Series A, Sustainability Bonds, 4.60%, 11/01/43		225		227,766
New York Power Authority, RB, Sustainability Bonds, (AGM), 4.00%, 11/15/42		1,000		1,031,112
New York State Housing Finance Agency, RB, M/F Housing, Sustainability Bonds, (SONYMA), 3.80%, 11/01/62(b)		735		730,726
New York Transportation Development Corp., RB, AMT, Sustainability Bonds, (AGM), 5.50%, 06/30/44		500		540,957
				6,527,292
North Carolina — 0.5%
North Carolina Housing Finance Agency, RB, S/F Housing, Sustainability Bonds, (FHLMC, FNMA, GNMA), 3.75%, 07/01/52		230		227,051
North Dakota — 0.9%
North Dakota Housing Finance Agency, RB, S/F Housing, Sustainability Bonds, 5.75%, 01/01/54		400		428,172
Oregon — 0.9%
Port of Portland Oregon Airport Revenue, Refunding ARB, Series 29, AMT, Sustainability Bonds, 5.50%, 07/01/48		410		455,496
Pennsylvania — 7.0%
City of Philadelphia Pennsylvania Water & Wastewater Revenue, RB, Series C, 5.50%, 06/01/47		1,000		1,125,016
Pennsylvania Housing Finance Agency, RB, S/F Housing, Series 143A, Sustainability Bonds, 6.25%, 10/01/53		475		521,860
Pennsylvania Housing Finance Agency, Refunding RB, S/F Housing, Series 2022, Sustainability Bonds, 4.25%, 10/01/52		455		457,689
Pittsburgh Water & Sewer Authority, RB, Series A, 1st Lien, (AGM), 5.00%, 09/01/48		225		241,813
Southeastern Pennsylvania Transportation Authority, RB, 5.25%, 06/01/47		1,000		1,111,343
				3,457,721

Security	Par (000)		Value
Tennessee — 0.4%
Tennessee Housing Development Agency, Refunding RB, S/F Housing, Series 1, Sustainability Bonds, 3.75%, 07/01/52	$	190	$	187,690
Texas — 6.2%
Arlington Higher Education Finance Corp., RB
(PSF), 5.00%, 08/15/47		500		534,317
Series A, 5.25%, 08/15/32		250		237,851
City of El Paso Texas Water & Sewer Revenue, Refunding RB, 5.00%, 03/01/46		1,000		1,079,838
Tarrant County Cultural Education Facilities Finance Corp., RB, Class F, 5.00%, 11/15/52(b)		415		458,999
Texas State Technical College, RB, (AGM), 5.50%, 08/01/42		665		765,214
				3,076,219
Utah — 3.6%
University of Utah, RB, Series A, Sustainability Bonds, 4.00%, 08/01/43		1,500		1,525,405
Utah Infrastructure Agency, RB, Series A, 5.00%, 10/15/32		250		264,160
				1,789,565
Vermont — 0.2%
East Central Vermont Telecommunications District, RB, Series A, 6.88%, 12/01/46(a)		115		118,550
Virginia — 2.1%
Henrico County Economic Development Authority, RB, Class A, 5.00%, 10/01/47		1,000		1,046,315
Total Long-Term Investments — 94.1% (Cost: $46,644,898)				46,673,787
	Shares
Short-Term Securities
Money Market Funds — 5.0%
BlackRock Liquidity Funds, MuniCash, Institutional Class, 2.97%(d)(e)		2,468,144		2,468,391
Total Short-Term Securities — 5.0% (Cost: $ 2,468,243)				2,468,391
Total Investments — 99.1% (Cost: $ 49,113,141)				49,142,178
Other Assets Less Liabilities — 0.9%			448,326
Net Assets — 100.0%			$ 49,590,504

^(a) Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933, as amended. These securities may be resold in transactions exempt from registration to qualified institutional investors.

^(b) Variable rate security. Interest rate resets periodically. The rate shown is the effective interest rate as of period end. Security description also includes the reference rate and spread if published and available.

^(c) Security is valued using significant unobservable inputs and is classified as Level 3 in the fair value hierarchy.

^(d) Affiliate of the Fund.

^(e) Annualized 7-day yield as of period end.

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Schedule of Investments(unaudited) (continued) February 29, 2024 BlackRock Impact Municipal Fund

For Fund compliance purposes, the Fund’s sector classifications refer to one or more of the sector sub-classifications used by one or more widely recognized market indexes or rating group indexes, and/or as defined by the investment adviser. These definitions may not apply for purposes of this report, which may combine such sector sub-classifications for reporting ease.

Affiliates

Investments in issuers considered to be affiliate(s) of the Fund during the period ended February 29, 2024 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliated Issuer	Value at 05/31/23		Purchases at Cost		Proceeds from Sale			Net Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)			Value at 02/29/24		Shares Held at 02/29/24		Income		Capital Gain Distributions from Underlying Funds
BlackRock Liquidity Funds, MuniCash, Institutional Class	$	3,006,316	$	—	$	(538,097)	(a)	$	379	$	(207	)	$	2,468,391		2,468,144	$	38,224	$	—

^(a)  Represents net amount purchased (sold).

Derivative Financial Instruments Outstanding as of Period End

Futures Contracts

Description	Number of Contracts		Expiration Date		Notional Amount (000)		Value/ Unrealized Appreciation (Depreciation)
Short Contracts
10-Year U.S. Treasury Note		17		06/18/24	$	1,879	$	(6,137	)
U.S. Long Bond		11		06/18/24		1,312		(15,316	)
5-Year U.S. Treasury Note		8		06/28/24		856		(2,388	)
							$	(23,841	)

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of financial instruments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial reporting purposes as follows:

• Level 1 – Unadjusted price quotations in active markets/exchanges for identical assets or liabilities that the Fund has the ability to access;

• Level 2 – Other observable inputs (including, but not limited to, quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market–corroborated inputs); and

• Level 3 – Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Valuation Committee’s assumptions used in determining the fair value of financial instruments).

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Investments classified within Level 3 have significant unobservable inputs used by the Valuation Committee in determining the price for Fair Valued Investments. Level 3 investments include equity or debt issued by privately held companies or funds. There may not be a secondary market, and/or there are a limited number of investors. The categorization of a value determined for financial instruments is based on the pricing transparency of the financial instruments and is not necessarily an indication of the risks associated with investing in those securities. For information about the Fund’s policy regarding valuation of financial instruments, refer to its most recent financial statements.

3

Schedule of Investments(unaudited) (continued) February 29, 2024 BlackRock Impact Municipal Fund

Fair Value Hierarchy as of Period End (continued)

The following table summarizes the Fund’s financial instruments categorized in the fair value hierarchy. The breakdown of the Fund’s financial instruments into major categories is disclosed in the Schedule of Investments above.

	Level 1			Level 2		Level 3		Total
Assets
Investments
Long-Term Investments
Municipal Bonds	$	—		$	46,599,811	$	73,976	$	46,673,787
Short-Term Securities
Money Market Funds		2,468,391			—		—		2,468,391
	$	2,468,391		$	46,599,811	$	73,976	$	49,142,178
Derivative Financial Instruments(a)
Liabilities
Interest Rate Contracts	$	(23,841	)	$	—	$	—	$	(23,841	)

^(a) Derivative financial instruments are futures contracts. Futures contracts are valued at the unrealized appreciation (depreciation) on the instrument.

Portfolio Abbreviation

AGM	Assured Guaranty Municipal Corp.
AMT	Alternative Minimum Tax
ARB	Airport Revenue Bonds
BAM	Build America Mutual Assurance Co.
COP	Certificates of Participation
FHLMC	Federal Home Loan Mortgage Corp.
FNMA	Federal National Mortgage Association
GNMA	Government National Mortgage Association
GO	General Obligation Bonds
M/F	Multi-Family
PSF	Permanent School Fund
Q-SBLF	Qualified School Bond Loan Fund
RB	Revenue Bond
S/F	Single-Family
SAW	State Aid Withholding
SONYMA	State of New York Mortgage Agency
ST	Special Tax

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