Blackrock Municipal Bond Fund NPORT-P BlackRock High Yield Municipal Fund (Sep 2020 report)

Schedule of Investments (unaudited)  September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Municipal Bonds
Alabama — 1.2%
Alabama Special Care Facilities Financing Authority-Birmingham Alabama, RB
5.75%, 06/01/35	$	200	$	202,048
5.75%, 06/01/45		355		350,644
6.00%, 06/01/50		450		451,098
Chelsea Park Cooperative District, SAB, 5.00%, 05/01/48		950		955,263
County of Jefferson AL Sewer Revenue, Refunding RB
Series A, Senior Lien, (AGM), 5.00%, 10/01/44		365		404,537
Series D, Sub-Lien, 7.00%, 10/01/51		2,355		2,761,167
Series D, Sub-Lien, 6.50%, 10/01/53		3,465		4,001,486
Tuscaloosa County Industrial Development Authority, Refunding RB, Series A, 5.25%, 05/01/44(a)		7,330		8,024,224
				17,150,467
Arizona — 2.8%
Arizona Industrial Development Authority, RB(a)
5.00%, 07/01/45		1,135		1,156,554
7.10%, 01/01/55		4,760		4,582,500
5.00%, 07/01/55		1,215		1,230,880
Series A, 5.00%, 07/01/39		1,270		1,308,392
Series A, 5.00%, 12/15/39		150		160,118
Series A, 5.00%, 07/01/49		2,790		2,818,960
Series A, 5.00%, 07/15/49		675		709,526
Series A, 5.00%, 12/15/49		345		360,283
Series A, 5.00%, 07/01/54		1,110		1,120,545
Series B, 5.13%, 07/01/47		420		441,756
Series B, 5.25%, 07/01/51		570		601,703
Arizona Industrial Development Authority, Refunding RB(a)
Series A, 5.00%, 07/01/26		760		820,868
Series A, 5.25%, 07/01/47		3,235		3,419,169
Series A, 5.50%, 07/01/52		2,970		3,176,712
Florence Town Inc Industrial Development Authority, RB, 6.00%, 07/01/43		1,375		1,442,059
Industrial Development Authority of the City of Phoenix, RB
5.00%, 07/01/54		1,330		1,381,059
5.00%, 07/01/59		655		678,508
Series A, 5.00%, 07/01/34(a)		250		256,473
Series A, 6.50%, 07/01/34(a)		465		509,612
Series A, 5.00%, 07/01/36(a)		1,225		1,297,826
Series A, 5.00%, 07/01/39(a)		205		209,061
Series A, 5.00%, 07/01/41(a)		1,685		1,760,370
Series A, 5.00%, 07/01/43		1,445		1,467,210
Series A, 6.75%, 07/01/44(a)		810		879,457
Series A, 5.25%, 07/01/48(a)		1,690		1,717,378
Series A, 5.00%, 07/01/49(a)		320		322,259
Series A, 5.00%, 07/01/54(a)		530		533,424
Industrial Development Authority of the City of Phoenix, Refunding RB(a)
5.00%, 07/01/35		615		650,543
5.00%, 07/01/45		1,500		1,557,005
Series A, 5.00%, 07/01/35		295		313,694

Security	Par (000)		Value
Arizona (continued)
Industrial Development Authority of the County of Pima, RB
5.13%, 07/01/39	$	700	$	701,225
5.25%, 07/01/49		870		848,955
La Paz County Industrial Development Authority, RB, 5.88%, 06/15/48(a)		1,340		1,369,788
				39,803,872
Arkansas(a) — 1.7%
Arkansas Development Finance Authority, RB
AMT, 4.50%, 09/01/49		15,880		15,992,113
AMT, 4.75%, 09/01/49		8,190		8,189,017
				24,181,130
California — 2.8%
California County Tobacco Securitization Agency, Refunding RB, Series A, 5.00%, 06/01/36		1,665		1,665,017
California Municipal Finance Authority, ARB, AMT, Senior Lien, 4.00%, 12/31/47		2,560		2,694,451
California Municipal Finance Authority, RB(a)
Series A, 5.50%, 08/01/34		310		327,425
Series A, 6.00%, 08/01/44		655		687,737
Series A, 6.13%, 08/01/49		570		598,255
California Municipal Finance Authority, Refunding RB, Series A, 5.00%, 02/01/42		345		401,501
California Pollution Control Financing Authority, Refunding RB, 5.00%, 11/21/45(a)		3,000		3,347,820
California School Finance Authority, RB
6.65%, 07/01/33		295		318,821
6.90%, 07/01/43		650		697,294
California Statewide Communities Development Authority, RB(a)
5.25%, 12/01/38		1,420		1,613,631
5.25%, 12/01/48		1,000		1,114,570
City of Chula Vista California, Refunding RB, Series A, 5.88%, 02/15/34		500		502,145
City of San Jose California Hotel Tax Revenue, RB
6.50%, 05/01/36		310		320,125
6.50%, 05/01/42		760		783,446
Golden State Tobacco Securitization Corp., Refunding RB
Series A-1, 3.50%, 06/01/36		5,860		5,959,268
Series A-1, 5.00%, 06/01/47		5,195		5,350,330
Series A-1, 5.25%, 06/01/47		945		977,612
Series A-2, 5.00%, 06/01/47		3,950		4,071,265
Hastings Campus Housing Finance Authority, RB, Series A, 6.75%, 07/01/61(a)(b)		4,420		1,737,458
Riverside County Transportation Commission, RB, Series A, Senior Lien, 5.75%, 06/01/48		2,115		2,336,779
San Francisco City & County Redevelopment Agency Successor Agency, ST, 0.00%, 08/01/43(c)		3,000		822,690
San Francisco City & County Redevelopment Agency Successor Agency, TA(a)
Series D, 0.00%, 08/01/23(c)		1,000		889,430
Series D, 0.00%, 08/01/26(c)		580		444,367
Series D, 0.00%, 08/01/31(c)		1,155		688,010
Sub-Series D, 3.00%, 08/01/21		500		505,905
				38,855,352

S C H E D U L E  O F  I N V E S T M E N T  S 1

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Colorado — 4.1%
9th Avenue Metropolitan District No.2, GO, 5.00%, 12/01/48	$	1,565	$	1,590,525
Aurora Crossroads Metropolitan District No.2, GO
Series A, 5.00%, 12/01/40		1,000		1,021,260
Series A, 5.00%, 12/01/50		500		503,190
Aviation Station North Metropolitan District No.2, GO
Series A, 5.00%, 12/01/39		750		765,023
Series A, 5.00%, 12/01/48		1,350		1,352,079
Broadway Station Metropolitan District No.2, GO
Series A, 5.00%, 12/01/35		735		747,150
Series A, 5.13%, 12/01/48		3,925		3,871,267
Bromley Park Metropolitan District No.2, Refunding GO, Sub-Series B, 6.38%, 12/15/47		937		873,706
Centerra Metropolitan District No.1, TA, 5.00%, 12/01/47(a)		820		823,206
Colorado Educational & Cultural Facilities Authority, RB
5.00%, 12/01/33		450		464,364
5.00%, 12/01/42		545		556,576
Colorado Health Facilities Authority, Refunding RB, Series A, 4.00%, 08/01/44		4,620		5,103,067
Colorado High Performance Transportation Enterprise, RB, 5.00%, 12/31/56		2,500		2,661,400
Constitution Heights Metropolitan District, Refunding GO, 5.00%, 12/01/49		1,260		1,265,897
Copperleaf Metropolitan District No.2, Refunding GO, 5.75%, 12/01/45		780		804,586
Copperleaf Metropolitan District No.3, GO
Series A, 5.00%, 12/01/37		500		513,835
Series A, 5.13%, 12/01/47		1,200		1,220,292
Green Gables Metropolitan District No.1, GO, Series A, 5.30%, 12/01/21(d)		1,000		1,058,750
Green Valley Ranch East Metropolitan District No.6, GO, Series A, 5.88%, 12/01/50		2,615		2,703,805
Home Place Metropolitan District, GO, Series A, 5.75%, 12/01/50		2,345		2,410,754
Jefferson Center Metropolitan District No.1, RB
Series A-2, 4.13%, 12/01/40		580		580,505
Series A-2, 4.38%, 12/01/47		1,000		1,000,860
Karl’s Farm Metropolitan District No.2, GO(a)
Series A, 5.38%, 12/01/40		515		518,198
Series A, 5.63%, 12/01/50		1,350		1,357,762
Leyden Rock Metropolitan District No.10, GO, Series A, 5.00%, 12/01/45		1,250		1,268,162
North Holly Metropolitan District, GO, Series A, 5.50%, 12/01/48		760		771,491
Palisade Metropolitan District No.2, GO, Subordinate, 7.25%, 12/15/49		2,825		2,462,863
Palisade Park West Metropolitan District, GO, Series A, 5.13%, 12/01/49		1,500		1,477,200
Pomponio Terrace Metropolitan District, GO, Series A, 5.00%, 12/01/49		1,450		1,400,975
Prairie Farm Metropolitan District, GO, Series A, 5.25%, 12/01/48		1,240		1,296,246
Regional Transportation District, RB
6.00%, 01/15/34		1,500		1,504,305
6.00%, 01/15/41		1,000		1,002,870
Southlands Metropolitan District No.1, Refunding GO
Series A-1, 5.00%, 12/01/37		1,115		1,182,034

Security	Par (000)		Value
Colorado (continued)
Southlands Metropolitan District No.1, Refunding GO (continued)
Series A-1, 5.00%, 12/01/47	$	3,990	$	4,176,014
Tallyn’s Reach Metropolitan District No.3, GO, Subordinate, 6.75%, 11/01/38		845		872,463
Thompson Crossing Metropolitan District No.4, Refunding GO
5.00%, 12/01/39		1,400		1,428,840
5.00%, 12/01/49		1,480		1,487,074
Timberleaf Metropolitan District, GO, Series A, 5.75%, 12/01/50		1,730		1,787,661
Westcreek Metropolitan District No.2, GO, Series A, 5.38%, 12/01/48		800		807,360
Wild Plum Metropolitan District, GO, Series A, 5.00%, 12/01/49		595		577,608
				57,271,223
Connecticut — 1.7%
Connecticut Housing Finance Authority, Refunding RB, S/F Housing
Series C-2, AMT, 2.00%, 05/15/30		175		173,763
Series C-2, AMT, 2.05%, 11/15/30		500		495,955
Series C-2, AMT, 2.15%, 11/15/31		400		393,792
Connecticut State Health & Educational Facilities Authority, RB(a)
Series A, 5.00%, 01/01/45		825		871,167
Series A, 5.00%, 01/01/55		1,100		1,146,838
Connecticut State Health & Educational Facilities Authority, Refunding RB
4.00%, 07/01/39		940		943,393
4.00%, 07/01/44		3,500		3,423,805
4.00%, 07/01/49		1,750		1,671,792
Mashantucket Western Pequot Tribe, 7.35%, 07/01/26		32,631		5,384,030
Mohegan Tribal Finance Authority, RB, 7.00%, 02/01/45(a)		3,795		3,602,252
Mohegan Tribe of Indians of Connecticut, RB, Series A, 6.75%, 02/01/45(a)		980		993,583
Mohegan Tribe of Indians of Connecticut, Refunding RB, Series C, 6.25%, 02/01/30(a)		2,045		2,194,408
State of Connecticut, GO, Series A, 4.00%, 04/15/37		1,800		2,078,262
				23,373,040
Delaware — 0.9%
County of Kent, RB, Series A, 5.00%, 07/01/58		1,500		1,456,005
Delaware State Economic Development Authority, RB
5.38%, 10/01/45		10,080		10,111,752
Series A, 5.00%, 06/01/46		1,000		1,019,980
				12,587,737
District of Columbia — 1.6%
District of Columbia Tobacco Settlement Financing Corp. Refunding RB, 6.75%, 05/15/40		385		396,234
District of Columbia Tobacco Settlement Financing Corp., RB(c)
Series A, 0.00%, 06/15/46		40,740		8,241,295
Series B, 0.00%, 06/15/46		43,620		5,243,560
Metropolitan Washington Airports Authority Dulles Toll Road Revenue, Refunding RB
Series A, 5.00%, 10/01/53		3,830		4,004,112

2

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
District of Columbia (continued)
Metropolitan Washington Airports Authority Dulles Toll Road Revenue, Refunding RB (continued)
Series B, 2nd Lien, (AGC), 0.00%, 10/01/30(c)	$	3,005	$	2,370,825
Series B, Subordinate, 4.00%, 10/01/49		2,170		2,380,403
				22,636,429
Florida — 8.5%
Alachua County Health Facilities Authority, RB, Series A, 5.00%, 12/01/44		1,720		1,956,707
Boggy Creek Improvement District, Refunding SAB, Series 2013, 5.13%, 05/01/43		1,260		1,283,423
Capital Region Community Development District, Refunding SAB, Series A-1, 5.13%, 05/01/39		2,280		2,503,645
Capital Trust Agency, Inc., RB
4.50%, 01/01/35(a)		2,250		2,214,180
5.00%, 07/01/49(a)		1,280		1,326,118
5.00%, 01/01/55(a)		4,350		4,284,010
Series A, 8.25%, 01/01/44(e)(f)		445		249,200
Series A, 8.25%, 01/01/49(e)(f)		950		532,000
Series A, 5.00%, 06/15/49(a)		500		531,520
Series A, 5.00%, 12/15/49		300		325,230
Series A, 5.75%, 01/01/50(e)(f)		570		570,000
Series A, 5.75%, 06/01/54(a)		1,925		1,952,739
Series A, 5.00%, 12/15/54		260		281,310
Series B, 0.00%, 01/01/35(c)		3,645		1,448,268
Series B, 0.00%, 01/01/60(c)		64,500		3,940,305
Celebration Pointe Community Development District, SAB
4.00%, 05/01/22(a)		150		152,469
4.75%, 05/01/24		315		327,080
5.00%, 05/01/34		1,180		1,235,118
Charles Cove Community Development District, SAB
3.25%, 05/01/25		300		301,215
3.75%, 05/01/30		360		366,602
4.25%, 05/01/40		975		990,454
4.38%, 05/01/50		1,505		1,526,777
Charlotte County Industrial Development Authority, RB(a)
AMT, 5.00%, 10/01/34		530		561,297
AMT, 5.00%, 10/01/49		2,510		2,542,605
City of Tallahassee Florida, RB, Series A, 5.00%, 12/01/55		2,600		2,852,226
Collier County Health Facilities Authority, RB, Series A, 5.00%, 05/01/48		2,090		2,430,357
Collier County Industrial Development Authority, Refunding RB, Series A, 8.13%, 05/15/44(a)(e)(f)		370		284,921
County of Lake Florida, RB(a)
5.00%, 01/15/39		550		578,474
5.00%, 01/15/49		825		851,367
5.00%, 01/15/54		830		855,207
County of Osceola Florida Transportation Revenue, Refunding RB
Sereis A-1, 4.00%, 10/01/54		2,500		2,653,175
Series A-2, 0.00%, 10/01/50(c)		1,770		592,277
Series A-2, 0.00%, 10/01/51(c)		2,125		684,250
Series A-2, 0.00%, 10/01/52(c)		2,125		657,326
Series A-2, 0.00%, 10/01/53(c)		5,675		1,685,645
Series A-2, 0.00%, 10/01/54(c)		2,125		606,241
County of Palm Beach Florida, RB, 5.00%, 04/01/51(a)		540		538,850

Security	Par (000)		Value
Florida (continued)
Escambia County Health Facilities Authority, Refunding RB, 4.00%, 08/15/45	$	6,530	$	7,093,343
Florida Development Finance Corp. RB
Series A, 5.75%, 06/15/29		695		764,848
Series A, 6.00%, 06/15/34		835		916,763
Series A, 6.13%, 06/15/44		3,185		3,453,846
AMT, 5.00%, 05/01/29(a)		3,300		3,510,837
Series A, AMT, 5.00%, 08/01/29(a)(g)		2,240		2,269,859
Grand Oaks Community Development District, SAB
4.25%, 05/01/40		915		903,544
4.50%, 05/01/52		1,015		1,011,245
Greater Orlando Aviation Authority, Refunding RB, AMT, 5.00%, 11/15/36		2,000		1,929,380
Greeneway Improvement District, SAB, 5.13%, 05/01/43		1,260		1,296,527
Hills Minneola Community Development District, SAB(a)
4.00%, 05/01/40		1,025		1,031,939
4.00%, 05/01/50		1,500		1,479,630
Lakewood Ranch Stewardship District, Refunding SAB, 8.00%, 05/01/21(d)		515		538,448
Lakewood Ranch Stewardship District, SAB
4.00%, 05/01/21		54		54,104
3.90%, 05/01/23		275		280,726
4.25%, 05/01/25		100		104,072
4.25%, 05/01/26		175		181,960
4.25%, 05/01/28		535		572,327
4.75%, 05/01/29		955		1,056,211
4.95%, 05/01/29(a)		665		743,450
4.88%, 05/01/35		265		280,585
5.00%, 05/01/38		1,175		1,281,420
3.75%, 05/01/39(a)		570		573,545
5.30%, 05/01/39		1,090		1,220,201
5.50%, 05/01/39(a)		670		759,820
3.75%, 05/01/40		525		523,892
4.88%, 05/01/45		545		568,680
5.13%, 05/01/46		1,005		1,058,104
5.10%, 05/01/48		2,545		2,748,473
5.45%, 05/01/48		1,935		2,156,016
5.65%, 05/01/48(a)		1,125		1,269,788
4.00%, 05/01/49(a)		355		357,840
3.90%, 05/01/50		525		517,104
Martin County Health Facilities Authority, RB, 5.50%, 11/15/21(d)		1,000		1,059,280
Miami-Dade County Industrial Development Authority, RB, 5.00%, 01/15/48		1,405		1,554,576
Mid-Bay Bridge Authority, RB, Series A, 7.25%, 10/01/21(d)		1,450		1,551,892
Midtown Miami Community Development District, Refunding SAB
Series A, 5.00%, 05/01/29		1,745		1,822,146
Series A, 5.00%, 05/01/37		890		918,640
Palm Beach County Health Facilities Authority, Refunding RB, Series A, 7.50%, 06/01/49		1,000		1,094,090
Pine Island Community Development District, RB, 0.00%, 11/01/24(c)		940		802,234
Pinellas County Industrial Development Authority, RB, 5.00%, 07/01/39		220		240,112
Santa Rosa Bay Bridge Authority, RB 6.25%, 07/01/28(e)(f)		345		273,130

S C H E D U L E  O F  I N V E S T M E N T  S 3

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Florida (continued)
Santa Rosa Bay Bridge Authority, RB (continued)
6.25%, 07/01/28	$	57	$	57,090
Seminole County Industrial Development Authority, Refunding RB
5.50%, 11/15/49		3,025		2,666,326
5.75%, 11/15/54		2,420		2,169,506
Southern Groves Community Development District No.5, SAB
3.38%, 05/01/25		405		410,962
4.00%, 05/01/30		235		247,187
4.30%, 05/01/40		895		916,059
4.50%, 05/01/46		650		665,184
Tolomato Community Development District, Refunding SAB
Series 2015-2, 6.61%, 05/01/40(b)		125		81,841
Series A-2, 4.25%, 05/01/37		915		892,299
Series A-4, Convertible, 6.61%, 05/01/40(b)		50		45,271
Tolomato Community Development District, SAB(e)(f)
Series 2015-1, 6.61%, 05/01/40(b)		205		172,838
Series 2015-3, 6.61%, 05/01/40		135		1
Series 3, 6.65%, 05/01/40		105		1
Trout Creek Community Development District, SAB
5.38%, 05/01/38		670		740,209
5.50%, 05/01/49		1,700		1,863,166
V-Dana Community Development District, SAB(a)
3.00%, 05/01/25		300		299,025
3.50%, 05/01/31		525		525,457
4.00%, 05/01/40		750		748,395
4.00%, 05/01/51		1,200		1,168,596
Viera East Community Development District, Refunding SAB, 5.00%, 05/01/26		640		677,779
Village Community Development District No.10, SAB, 5.13%, 05/01/43		1,525		1,562,469
Village Community Development District No.9, SAB
7.00%, 05/01/41		1,235		1,258,020
5.50%, 05/01/42		470		482,507
West Villages Improvement District, SAB
4.25%, 05/01/29		400		425,504
4.75%, 05/01/39		885		948,030
5.00%, 05/01/50		1,415		1,517,517
				119,038,454
Georgia — 1.3%
Clayton County Development Authority, Refunding RB, Series A, 8.75%, 06/01/29		593		597,010
Gainesville & Hall County Hospital Authority, Refunding RB, Series A, (GTD), 5.50%, 08/15/54		555		644,977
Main Street Natural Gas, Inc., RB
Series A, 5.00%, 05/15/35		1,020		1,364,423
Series A, 5.00%, 05/15/36		1,020		1,374,226
Series A, 5.00%, 05/15/37		1,120		1,521,733
Series A, 5.00%, 05/15/38		615		842,175
Series A, 5.00%, 05/15/49		2,055		2,906,777
Municipal Electric Authority of Georgia, RB
4.00%, 01/01/49		4,150		4,602,474
Series A, 5.00%, 01/01/49		3,235		3,877,439
Series A, 5.00%, 01/01/59		525		625,154
				18,356,388

Security	Par (000)		Value
Guam — 0.2%
Guam Government Waterworks Authority, RB, Series A, 5.00%, 01/01/50	$	2,445	$	2,929,721
Idaho — 0.4%
Idaho Health Facilities Authority, Refunding RB
3.50%, 09/01/33		375		377,164
5.00%, 09/01/37		1,000		1,070,830
Idaho Housing & Finance Association, RB(a)
5.00%, 12/01/46		1,000		1,077,300
Series A, 6.00%, 07/01/39		370		419,832
Series A, 6.00%, 07/01/49		595		657,624
Series A, 6.00%, 07/01/54		570		627,718
Series A, 6.95%, 06/15/55		1,540		1,578,007
Power County Industrial Development Corp., RB, AMT, 6.45%, 08/01/32		265		266,158
				6,074,633
Illinois — 6.7%
Chicago Board of Education, GO
Series A, 5.00%, 12/01/42		1,570		1,610,804
Series C, 5.25%, 12/01/39		2,250		2,388,937
Series D, 5.00%, 12/01/46		3,620		3,798,304
Series H, 5.00%, 12/01/46		725		779,477
Chicago Board of Education, Refunding GO
Series A, 0.00%, 12/01/25(c)		590		507,925
Series A, 5.00%, 12/01/28		530		599,075
Series A, 5.00%, 12/01/29		660		746,500
Series A, 5.00%, 12/01/30		2,210		2,485,985
Series B, 4.00%, 12/01/35		1,155		1,162,126
Series C, 5.00%, 12/01/25		1,220		1,352,297
Series C, 5.00%, 12/01/30		1,370		1,508,110
Series D, 5.00%, 12/01/31		1,500		1,642,470
Series G, 5.00%, 12/01/44		3,700		3,989,562
Chicago O’Hare International Airport, ARB, AMT, 5.00%, 07/01/48		2,000		2,232,420
City of Chicago Illinois, Refunding GO
Series A, 5.25%, 01/01/32		2,315		2,386,950
Series A, 6.00%, 01/01/38		3,870		4,219,345
Series B, 5.43%, 01/01/42		9,215		8,794,427
Illinois Finance Authority, RB, Series A, 6.00%, 10/01/48		1,700		1,759,007
Illinois Finance Authority, Refunding RB
6.00%, 02/01/34		335		351,556
4.00%, 09/01/35		1,000		1,024,760
4.00%, 09/01/37		1,000		1,009,170
4.00%, 09/01/39		2,000		2,018,420
4.75%, 10/15/40(a)(g)		6,800		6,889,012
4.00%, 09/01/41		1,250		1,234,013
6.13%, 02/01/45		790		818,606
Series C, 5.00%, 02/15/36		1,805		2,161,199
Series C, 5.00%, 02/15/41		3,000		3,550,200
Metropolitan Pier & Exposition Authority, RB
Series A, 0.00%, 12/15/52(c)		4,520		1,122,271
Series A, 5.50%, 06/15/53		3,925		4,276,405
Series A, 0.00%, 12/15/56(c)		7,645		1,564,167
Series A, 5.00%, 06/15/57		4,555		4,938,394
Metropolitan Pier & Exposition Authority, Refunding RB(c)
Series B, (AGM), 0.00%, 06/15/44		3,455		1,497,224
Series B, 0.00%, 12/15/54		38,935		8,749,473

4

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Illinois (continued)
Quad Cities Regional Economic Development Authority, Refunding RB, 4.75%, 10/01/32	$	675	$	713,009
State of Illinois, GO
5.50%, 05/01/30		1,235		1,430,908
5.00%, 03/01/35		1,095		1,112,400
5.00%, 02/01/39		510		523,331
5.50%, 05/01/39		2,460		2,722,285
Series A, 5.00%, 04/01/35		1,460		1,488,762
Series A, 5.00%, 04/01/38		2,190		2,226,814
				93,386,100
Indiana — 1.1%
City of Anderson Indiana, RB, 5.38%, 01/01/40		1,540		1,538,753
City of Valparaiso Indiana, RB
AMT, 6.75%, 01/01/34		525		571,000
AMT, 7.00%, 01/01/44		1,270		1,398,384
City of Vincennes Indiana, Refunding RB, 6.25%, 01/01/29(a)		2,755		2,768,059
County of Allen Indiana, RB(a)
Series A-1, 6.63%, 01/15/34		430		406,978
Series A-1, 6.75%, 01/15/43		1,220		1,151,265
Series A-1, 6.88%, 01/15/52		1,270		1,221,588
Indiana Finance Authority, RB
Series A, AMT, 5.00%, 07/01/44		370		392,304
Series A, AMT, 5.00%, 07/01/48		1,230		1,304,157
Series A, AMT, 5.25%, 01/01/51		2,500		2,663,725
Indiana Finance Authority, Refunding RB, 5.00%, 03/01/39		725		735,737
Town of Chesterton Indiana, RB, Series A-1, 6.38%, 01/15/51(a)(e)(f)		1,745		1,594,057
				15,746,007
Iowa — 0.8%
Iowa Finance Authority, RB, Series A, 5.00%, 05/15/48		2,360		2,475,947
Iowa Finance Authority, Refunding RB
3.13%, 12/01/22		3,090		3,078,845
Series A, 5.25%, 12/01/50(g)		595		624,506
Iowa Tobacco Settlement Authority, Refunding RB
Series C, 5.38%, 06/01/38		3,075		3,078,751
Series C, 5.50%, 06/01/42		2,030		2,032,477
				11,290,526
Kentucky — 0.3%
Kentucky Economic Development Finance Authority, Refunding RB, Series B, (NPFGC), 0.00%, 10/01/24(c)		250		234,235
Kentucky Public Transportation Infrastructure Authority, RB, Series A, 6.00%, 07/01/53		3,000		3,295,170
				3,529,405
Louisiana — 2.0%
Juban Crossing Economic Development District, Refunding RB, Series C, 7.00%, 09/15/44(a)		3,075		2,755,139
Louisiana Local Government Environmental Facilities & Community Development Auth, RB
5.00%, 07/01/54(a)		1,990		1,996,706
Series A-2, 6.50%, 11/01/35		1,630		1,636,748
Louisiana Public Facilities Authority, RB
6.75%, 05/01/21(d)		645		669,497
4.00%, 06/01/50		2,665		2,988,824

Security	Par (000)		Value
Louisiana (continued)
Louisiana Public Facilities Authority, RB (continued)
Series A, 5.00%, 04/01/49(a)	$	500	$	501,440
Louisiana Public Facilities Authority, Refunding RB, 4.00%, 04/01/50		12,320		13,819,098
Parish of St James, RB, Series 2, 6.35%, 07/01/40(a)		3,160		3,725,261
				28,092,713
Maine — 0.1%
Maine Health & Higher Educational Facilities Authority, RB, 6.75%, 07/01/41		1,075		1,096,833
Maryland — 1.3%
City of Baltimore Maryland, Refunding RB, Series A, 4.00%, 09/01/27		325		330,788
County of Frederick Maryland, Refunding TA, 4.63%, 07/01/43(a)		5,100		5,065,473
Maryland Economic Development Corp., RB, Series D, AMT, 5.00%, 03/31/51		3,135		3,020,259
Maryland Economic Development Corp., Refunding RB, 5.00%, 07/01/39		950		993,311
Maryland Health & Higher Educational Facilities Authority, RB, Series A, 7.00%, 03/01/55(a)		8,165		9,110,507
				18,520,338
Massachusetts — 0.8%
Massachusetts Development Finance Agency, RB
Series B, 0.00%, 11/15/56(c)		94		13,807
Series D, 4.00%, 07/01/45		715		745,166
Massachusetts Development Finance Agency, Refunding RB
4.00%, 10/01/32(a)		355		356,140
4.13%, 10/01/42(a)		855		837,378
Series A, 5.00%, 07/01/38		1,200		1,402,548
Series A, 5.00%, 07/01/39		3,055		3,561,214
Series A, 5.00%, 07/01/44		3,750		4,334,662
				11,250,915
Michigan — 0.5%
Advanced Technology Academy, Refunding RB
3.50%, 11/01/24		250		252,815
3.88%, 11/01/29		150		153,421
5.00%, 11/01/34		400		431,920
5.00%, 11/01/44		160		165,310
City of Detroit Michigan, GO
5.00%, 04/01/34		485		506,937
5.00%, 04/01/35		485		505,375
5.00%, 04/01/36		340		353,114
5.00%, 04/01/37		545		564,206
5.00%, 04/01/38		240		247,714
Kentwood Economic Development Corp., Refunding RB, 5.63%, 11/15/41		1,000		1,025,870
Michigan Finance Authority, RB(d)
Series C-2, AMT, Senior Lien, 5.00%, 07/01/22		350		378,675
Series C-1, Senior Lien, 5.00%, 07/01/22		800		867,432
Michigan Strategic Fund, RB, AMT, 5.00%, 06/30/48		2,030		2,247,738
				7,700,527
Minnesota — 1.2%
City of Cologne Minnesota,RB, Series A, 5.00%, 07/01/45		2,065		2,175,705
City of Deephaven Minnesota, Refunding RB, Series A, 5.25%, 07/01/40		500		543,590

S C H E D U L E  O F  I N V E S T M E N T  S 5

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Minnesota (continued)
City of Minneapolis Minnesota, RB
Series A, 5.00%, 07/01/55	$	1,405	$	1,426,440
Series A, 5.75%, 07/01/55		3,435		3,609,052
Duluth Economic Development Authority, Refunding RB
Series A, 4.25%, 02/15/48		1,925		2,111,282
Series A, 5.25%, 02/15/53		3,850		4,507,811
Housing & Redevelopment Authority of The City of St Paul Minnesota, RB
5.00%, 07/01/49		555		612,759
5.00%, 07/01/55		870		958,879
Series A, 6.63%, 09/01/21(d)		500		529,495
				16,475,013
Missouri — 0.9%
Health & Educational Facilities Authority of the State of Missouri, Refunding RB, Series A, 4.00%, 11/15/48		3,650		4,069,312
Industrial Development Authority of the City of St Louis Missouri, Refunding RB
Series A, 4.38%, 11/15/35		1,020		877,037
Series A, 4.75%, 11/15/47		1,135		962,639
Kansas City Industrial Development Authority, Refunding RB(a)(e)(f)
5.75%, 11/15/36		1,350		471,389
6.00%, 11/15/51		110		38,409
Kansas City Land Clearance Redevelopment Authority, TA(a)
Series B, 4.38%, 02/01/31		3,245		3,310,744
Series B, 5.00%, 02/01/40		1,240		1,278,105
Poplar Bluff Regional Transportation Development District, RB, 4.75%, 12/01/42		2,200		2,252,118
				13,259,753
Nebraska — 0.7%
Central Plains Energy Project, RB, 5.00%, 09/01/42		780		845,575
Central Plains Energy Project, Refunding RB, Series A, 5.00%, 09/01/42		6,090		8,445,246
				9,290,821
Nevada — 0.1%
City of Las Vegas NV Special Improvement District No.815, SAB, 5.00%, 12/01/49		810		845,195
County of Clark Nevada, Refunding SAB
4.00%, 08/01/22		535		567,758
4.00%, 08/01/23		330		350,057
				1,763,010
New Hampshire(a) — 0.5%
New Hampshire Business Finance Authority, Refunding RB
Series B, 4.63%, 11/01/42		4,650		4,761,460
Series C, AMT, 4.88%, 11/01/42		2,515		2,591,557
				7,353,017
New Jersey — 6.0%
Casino Reinvestment Development Authority, Inc., Refunding RB, 5.25%, 11/01/44		5,750		5,864,655
Industrial Pollution Control Financing Authority of Gloucester County, Refunding RB, Series A, AMT, 5.00%, 12/01/24		1,270		1,324,191
New Jersey Economic Development Authority, RB
4.00%, 11/01/38		1,455		1,523,210

Security	Par (000)		Value
New Jersey (continued)
New Jersey Economic Development Authority, RB (continued)
4.00%, 11/01/39	$	1,165	$	1,214,932
6.00%, 10/01/43		970		1,049,394
Series A, 5.00%, 07/01/32		235		234,145
Series A, 5.00%, 07/01/37		375		363,847
Series A, 5.25%, 11/01/54(a)		3,955		3,850,707
Series B, 5.00%, 06/15/43		3,755		4,264,328
Series EEE, 5.00%, 06/15/43		5,550		6,302,802
AMT, 5.13%, 09/15/23		1,520		1,567,014
AMT, 5.38%, 01/01/43		1,360		1,485,827
Series B, AMT, 6.50%, 04/01/31		2,750		2,921,160
New Jersey Economic Development Authority, Refunding RB, 4.00%, 06/15/36		5,000		5,408,150
New Jersey Health Care Facilities Financing Authority, Refunding RB
5.00%, 07/01/32		1,140		1,374,384
5.00%, 07/01/33		1,450		1,741,914
New Jersey Housing & Mortgage Finance Agency, Refunding RB, Series E, 2.45%, 10/01/50		1,500		1,466,835
New Jersey Transportation Trust Fund Authority, RB
Series AA, 5.25%, 06/15/41		1,265		1,389,058
Series AA, 5.00%, 06/15/44		1,005		1,070,084
Series BB, 4.00%, 06/15/50		10,940		11,450,242
Series BB, 5.00%, 06/15/50		8,560		9,670,746
Series S, 5.25%, 06/15/43		4,095		4,758,431
New Jersey Transportation Trust Fund Authority, Refunding RB, Series A, 5.00%, 12/15/36		1,195		1,381,599
South Jersey Port Corp., ARB, Series B, AMT, 5.00%, 01/01/36		575		636,427
Tobacco Settlement Financing Corp., Refunding RB
Series A, 5.25%, 06/01/46		900		1,062,396
Sub-Series B, 5.00%, 06/01/46		10,000		11,278,900
				84,655,378
New Mexico — 0.2%
New Mexico Hospital Equipment Loan Council, Refunding RB, 5.50%, 07/01/42		2,030		2,129,572
NewYork — 7.3%
Build NYC Resource Corp. Refunding RB, AMT, 5.00%, 01/01/35(a)		1,215		1,310,062
Chautauqua Tobacco Asset Securitization Corp. Refunding RB, 5.00%, 06/01/48		4,475		4,484,800
City of New York Water & Sewer System, RB, Series 3, 5.40%, 01/01/21(e)(f)(g)		207		147,282
Erie Tobacco Asset Securitization Corp. Refunding RB, Series A, 5.00%, 06/01/45		3,210		3,210,032
Metropolitan Transportation Authority, Refunding RB
Series C-1, 4.75%, 11/15/45		4,115		4,289,229
Series C-1, 5.00%, 11/15/50		1,340		1,426,564
Series C-1, 5.25%, 11/15/55		1,980		2,137,469
New York Counties Tobacco Trust IV, Refunding RB
Series A, 6.25%, 06/01/41(a)		8,000		8,008,800
Series A, 5.00%, 06/01/42		4,520		4,537,402
Series A, 5.00%, 06/01/45		1,695		1,694,932
New York Counties Tobacco Trust VI, Refunding RB
Series A-2-B, 5.00%, 06/01/45		4,010		4,064,376
Series A-2-B, 5.00%, 06/01/51		6,865		6,954,657
New York Liberty Development Corp., Refunding RB(a)
Class 1, 5.00%, 11/15/44		12,115		12,427,930

6

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
NewYork (continued)
New York Liberty Development Corp., Refunding RB(a) (continued)
Class 2, 5.15%, 11/15/34	$	450	$	472,536
Class 2, 5.38%, 11/15/40		1,070		1,119,669
New York State Dormitory Authority, Refunding RB(a)
5.00%, 12/01/33		590		687,486
5.00%, 12/01/35		785		905,364
New York Transportation Development Corp., ARB, Series A, AMT, 5.25%, 01/01/50		3,000		3,232,440
New York Transportation Development Corp., RB
AMT, 5.00%, 10/01/35		1,295		1,385,780
AMT, 4.00%, 01/01/36		5,000		4,861,600
AMT, 5.00%, 10/01/40		3,650		3,878,234
AMT, 4.38%, 10/01/45		240		240,214
New York Transportation Development Corp., Refunding ARB, AMT, 5.38%, 08/01/36		3,665		3,805,113
Niagara Area Development Corp., Refunding RB, Series A, AMT, 4.75%, 11/01/42(a)		530		536,779
Port Authority of New York & New Jersey, ARB, 221st Series, AMT, 4.00%, 07/15/60		16,595		18,250,019
Triborough Bridge & Tunnel Authority, RB
Series A, 4.00%, 11/15/54		670		767,606
Series A, 5.00%, 11/15/54		2,140		2,677,568
Westchester County Healthcare Corp, RB, Series A, Senior Lien, 5.00%, 11/01/44		1,348		1,467,448
Westchester Tobacco Asset Securitization Corp., Refunding RB
Sub-Series C, 4.00%, 06/01/42		935		989,651
Sub-Series C, 5.13%, 06/01/51		2,000		2,175,120
				102,146,162
North Carolina — 0.4%
North Carolina State Education Assistance Authority, RB, AMT, 3.13%, 06/01/39		2,125		2,049,796
North Carolina Turnpike Authority, RB, Senior Lien, 4.00%, 01/01/55		3,000		3,280,380
				5,330,176
North Dakota — 0.1%
County of Cass North Dakota, Refunding RB, Series B, 5.25%, 02/15/58		1,785		2,089,503
Ohio — 3.8%
Buckeye Tobacco Settlement Financing Authority, Refunding RB, Series B-2, Class 2, 5.00%, 06/01/55		25,985		27,542,801
Butler County Port Authority, RB(a)
Series A-1, 6.25%, 01/15/34		1,575		1,517,827
Series A-1, 6.38%, 01/15/43		840		788,651
County of Hamilton Ohio, Refunding RB, 5.00%, 01/01/46		1,435		1,473,027
Franklin County Convention Facilities Authority, RB
5.00%, 12/01/44		1,800		1,819,062
5.00%, 12/01/51		4,000		3,929,880
Hickory Chase Community Authority, Refunding RB, 5.00%, 12/01/40(a)		1,890		1,905,555
Ohio Air Quality Development Authority, RB, AMT, 5.00%, 07/01/49(a)		5,000		5,065,850

Security	Par (000)		Value
Ohio (continued)
Port of Greater Cincinnati Development Authority, RB, M/F Housing, Series A, 5.25%, 12/01/50	$	740	$	443,023
Southern Ohio Port Authority, RB, Series A, AMT, 7.00%, 12/01/42(h)		5,980		5,968,399
State of Ohio, RB, AMT, 5.00%, 06/30/53		2,410		2,640,155
				53,094,230
Oklahoma — 1.1%
Norman Regional Hospital Authority, RB, 4.00%, 09/01/45		3,565		3,859,790
Oklahoma Development Finance Authority, RB
Series B, 5.00%, 08/15/38		4,585		5,325,844
Series B, 5.25%, 08/15/43		4,130		4,824,996
Tulsa County Industrial Authority, Refunding RB, 5.25%, 11/15/37		1,050		1,120,235
				15,130,865
Oregon — 0.7%
Medford Hospital Facilities Authority, Refunding RB
Series A, 4.00%, 08/15/50		4,845		5,469,375
Series A, 5.00%, 08/15/50		2,000		2,466,340
Oregon State Facilities Authority, RB(a)
Series A, 5.00%, 06/15/49		915		837,600
Series A, 5.25%, 06/15/55		505		476,357
				9,249,672
Pennsylvania — 1.9%
Allentown Neighborhood Improvement Zone Development Authority, Refunding RB
Series A, 5.00%, 05/01/35		1,185		1,226,416
Series A, 5.00%, 05/01/42		2,730		2,811,927
City of Philadelphia PAWater & Wastewater Revenue, RB, Series A, 5.00%, 11/01/50		6,000		7,572,660
East Hempfield Township Industrial Development Authority, RB
5.00%, 07/01/34		1,000		1,019,750
5.00%, 07/01/46		1,750		1,768,638
Montgomery County Higher Education and Health Authority, Refunding RB, Series A, 4.00%, 09/01/49		880		946,308
Montgomery County Industrial Development Authority, Refunding RB
5.00%, 12/01/46		1,470		1,531,578
5.38%, 01/01/50		1,865		1,855,824
Northampton County Industrial Development Authority, TA, 7.00%, 07/01/32		1,120		1,198,198
Pennsylvania Economic Development Financing Authority, RB, AMT, 5.00%, 06/30/42		895		995,643
Pennsylvania Economic Development Financing Authority, Refunding RB, AMT, 5.50%, 11/01/44		5,390		5,504,861
				26,431,803
Puerto Rico — 11.3%
Children’s Trust Fund, RB(c)
Series A, 0.00%, 05/15/57		63,950		4,127,333
Series B, 0.00%, 05/15/57		224,735		8,881,527
Children’s Trust Fund, Refunding RB, Series B, 0.00%, 05/15/55(c)		2,000		169,920
Commonwealth of Puerto Rico, GO(e)(f)
Series A, 5.25%, 07/01/22		335		240,936

S C H E D U L E  O F  I N V E S T M E N T  S 7

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Puerto Rico (continued)
Commonwealth of Puerto Rico, GO(e)(f) (continued)
Series A, 5.00%, 07/01/23	$	1,250	$	899,016
Series A, 5.13%, 07/01/31		215		154,631
Series A, 6.00%, 07/01/38		1,210		880,159
Series B, 5.25%, 07/01/17		1,060		722,717
Commonwealth of Puerto Rico, Refunding GO
Series A, 5.25%, 07/01/16(e)(f)		1,135		773,852
Series A, 5.50%, 07/01/18(e)(f)		200		136,362
Series A, 5.50%, 07/01/26		1,000		658,125
Series A, 8.00%, 07/01/35(e)(f)		15,486		9,766,788
Series A, 5.50%, 07/01/39(e)(f)		4,285		2,820,066
Series A, 6.50%, 07/01/40(e)(f)		2,610		1,898,524
Series A, 5.00%, 07/01/41(e)(f)		7,715		4,895,198
Series A, 5.75%, 07/01/41(e)(f)		385		263,437
Series C, 6.00%, 07/01/39(e)(f)		168		122,204
Series C, 6.50%, 07/01/40(e)(f)		400		290,962
Puerto Rico Commonwealth Aqueduct & Sewer Authority, RB
Series A, Senior Lien, 5.75%, 07/01/37		1,565		1,611,840
Series A, Senior Lien, 5.25%, 07/01/42		4,890		4,993,081
Puerto Rico Electric Power Authority, 7.50%, 01/01/21(e)(f)(g)		4,430		3,255,309
Puerto Rico Electric Power Authority, RB
Series A, 7.25%, 07/01/30(e)(f)		250		183,711
Series A, 7.00%, 07/01/33(e)(f)		8,735		6,418,862
Series A, 6.75%, 07/01/36(e)(f)		5,165		3,795,469
Series A, 7.00%, 07/01/40(e)(f)		1,000		734,844
Series A, 5.00%, 07/01/42(e)(f)		2,315		1,641,773
Series A, 5.05%, 07/01/42(e)(f)		1,080		765,924
Series A, 7.00%, 07/01/43(e)(f)		775		569,504
Series A-3, 10.00%, 07/01/19(e)(f)		748		553,274
Series B-3, 10.00%, 07/01/19(e)(f)		748		553,274
Series C-1, 5.40%, 01/01/18(e)(f)		2,054		1,456,799
Series C-2, 5.40%, 07/01/18(e)(f)		2,054		1,457,035
Series C-4, 5.40%, 07/01/20(e)(f)		208		147,282
Series CCC, 5.00%, 07/01/22(e)(f)		715		507,070
Series CCC, 5.00%, 07/01/25(e)(f)		620		439,697
Series CCC, 5.25%, 07/01/26(e)(f)		590		418,422
Series CCC, 5.25%, 07/01/28		1,605		1,043,250
Series CCC, 5.25%, 07/01/28(e)(f)		340		241,124
Series TT, 5.00%, 07/01/25(e)(f)		3,270		2,319,048
Series TT, 5.00%, 07/01/26(e)(f)		455		322,681
Series TT, 5.00%, 07/01/32(e)(f)		380		269,492
Series WW, 5.50%, 07/01/19(e)(f)		890		631,178
Series WW, 5.38%, 07/01/24(e)(f)		815		577,989
Series WW, 5.25%, 07/01/25(e)(f)		1,940		1,375,827
Series WW, 5.25%, 07/01/33(e)(f)		315		223,395
Series WW, 5.50%, 07/01/38(e)(f)		415		294,313
Series WW, 5.50%, 07/01/49(e)(f)		335		237,578
Series XX, 5.25%, 07/01/27(e)(f)		230		163,113
Series XX, 5.25%, 07/01/35(e)(f)		705		499,978
Series XX, 5.75%, 07/01/36(e)(f)		200		141,838
Series XX, 5.25%, 07/01/40(e)(f)		8,385		5,946,550
Puerto Rico Electric Power Authority, Refunding RB
Series AAA, 5.25%, 07/01/22(e)(f)		765		542,530
Series AAA, 5.25%, 07/01/24(e)(f)		170		120,562
Series AAA, 5.25%, 07/01/25(e)(f)		1,695		1,202,075
Series AAA, 5.25%, 07/01/28		2,000		1,300,000
Series AAA, 5.25%, 07/01/28(e)(f)		1,655		1,173,708
Series AAA, 5.25%, 07/01/29(e)(f)		190		134,746

Security	Par (000)		Value
Puerto Rico (continued)
Puerto Rico Electric Power Authority, Refunding RB (continued)
Series UU, 1.00%, 07/01/19(e)(f)(g)	$	125	$	81,250
Series UU, 1.16%, 07/01/19(e)(f)(g)		140		91,000
Series UU, 1.00%, 07/01/20(e)(f)(g)		1,135		734,913
Series UU, 3.47%, 02/15/21(g)		2,520		1,631,700
Series UU, 0.85%, 07/01/31(e)(f)(i)		1,345		870,888
Series ZZ, 5.25%, 07/01/19(e)(f)		1,050		744,648
Series ZZ, 5.25%, 07/01/21(e)(f)		90		63,827
Series ZZ, 5.25%, 07/01/23		370		240,500
Series ZZ, 5.25%, 07/01/24		4,345		2,824,250
Series ZZ, 5.25%, 07/01/24(e)(f)		705		499,978
Series ZZ, 5.25%, 07/01/25(e)(f)		265		187,935
Series ZZ, 5.25%, 07/01/26(e)(f)		85		60,281
Series ZZ, 5.00%, 07/01/28(e)(f)		345		244,670
Series ZZ, 5.00%, 07/01/49(e)(f)		330		234,032
Puerto Rico Public Buildings Authority, Refunding RB(e)(f)
Series F, (GTD), 5.25%, 07/01/24		1,495		1,192,263
Series G, (GTD), 4.75%, 07/01/32		1,230		980,925
Series M, (GTD), 6.25%, 07/01/31		2,000		1,640,834
Puerto Rico Sales Tax Financing Corp Sales Tax Revenue, RB
Series A-1, Restructured, 0.00%, 07/01/29(c)		397		311,284
Series A-1, Restructured, 0.00%, 07/01/31(c)		615		448,833
Series A-1, Restructured, 0.00%, 07/01/33(c)		679		453,110
Series A-1, Restructured, 0.00%, 07/01/46(c)		35,524		10,029,136
Series A-1, Restructured, 0.00%, 07/01/51(c)		10,548		2,151,687
Series A-1, Restructured, 4.75%, 07/01/53		12,864		13,387,308
Series A-1, Restructured, 5.00%, 07/01/58		12,904		13,633,979
Series A-2, Restructured, 4.33%, 07/01/40		9,257		9,451,489
Series A-2, Restructured, 4.54%, 07/01/53		1,564		1,606,588
Series A-2, Restructured, 4.78%, 07/01/58		7,333		7,637,833
Series B-1, Restructured, 0.00%, 07/01/46(c)		2,066		582,054
				157,983,097
Rhode Island — 1.4%
Tobacco Settlement Financing Corp, Refunding RB
Series A, 5.00%, 06/01/35		1,005		1,124,575
Series A, 5.00%, 06/01/40		5,500		6,080,745
Series B, 4.50%, 06/01/45		6,350		6,635,940
Series B, 5.00%, 06/01/50		5,650		6,041,319
				19,882,579
South Carolina — 1.9%
South Carolina Jobs-Economic Development Authority, RB
Series A, 5.00%, 11/15/42		585		593,172
Series A, 5.00%, 11/15/54		280		280,860
South Carolina Jobs-Economic Development Authority, Refunding RB
4.00%, 11/15/27		755		749,262
Series A, 5.00%, 05/01/48		5,825		6,714,186
South Carolina Public Service Authority, RB, Series E, 5.50%, 12/01/53		3,475		3,887,205
South Carolina Public Service Authority, Refunding RB, Series A, 5.00%, 12/01/50		13,005		14,632,576
				26,857,261

8

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Tennessee — 1.0%
Chattanooga Health Educational & Housing Facility Board, Refunding RB, Series A, 4.00%, 08/01/44	$	410	$	452,718
Franklin Health & Educational Facilities Board, Refunding RB, Series A, 7.50%, 06/01/47(a)(e)(f)		4,060		2,626,601
Knox County Health Educational & Housing Facility Board, Refunding RB, 5.00%, 04/01/36		560		646,430
Memphis-Shelby County Industrial Development Board, Refunding TA
Series A, 5.50%, 07/01/37		1,650		1,601,193
Series A, 5.63%, 01/01/46		1,875		1,758,319
Metropolitan Government Nashville & Davidson County Health & Educational Facs Bd, RB, Series A, 5.00%, 07/01/40		925		1,073,379
Metropolitan Government Nashville & Davidson County Health & Educational Facs Bd, Refunding RB
Series A, 4.00%, 10/01/49		1,635		1,551,697
Series A, 5.25%, 10/01/58		3,335		3,588,993
Nashville Metropolitan Development & Housing Agency, TA, 5.13%, 06/01/36(a)		500		517,725
				13,817,055
Texas — 5.2%
Arlington Higher Education Finance Corp., RB
5.63%, 08/15/54(a)		6,260		6,297,122
Series A, 5.88%, 03/01/24		425		446,841
Series A, 4.63%, 08/15/46		830		834,789
Brazoria County Industrial Development Corp., RB, AMT, 7.00%, 03/01/39		1,610		1,624,522
Central Texas Regional Mobility Authority, Refunding RB(c)
0.00%, 01/01/28		3,000		2,665,440
0.00%, 01/01/29		500		429,150
0.00%, 01/01/30		1,330		1,101,506
0.00%, 01/01/31		4,000		3,197,400
City of Houston Texas Airport System Revenue, RB
AMT, 5.00%, 07/15/28		2,725		2,800,210
Series A, AMT, 6.63%, 07/15/38		1,110		1,127,593
City of Houston Texas Airport System Revenue, Refunding ARB, AMT, 5.00%, 07/15/27		615		634,145
City of Houston Texas Airport System Revenue, Refunding RB, Series C, AMT, 5.00%, 07/15/27		3,925		4,008,838
Fort Bend County Industrial Development Corp., RB, Series B, 4.75%, 11/01/42		3,380		3,517,262
Harris County Cultural Education Facilities Finance Corp., Refunding RB
Series A, 5.00%, 01/01/38		510		518,338
Series A, 5.00%, 01/01/43		520		526,786
Series A, 5.13%, 01/01/48		1,535		1,554,955
Harris County-Houston Sports Authority, Refunding RB, Series G, Senior Lien, (NPFGC), 0.00%, 11/15/41(c)		350		130,148
Hemphill County Hospital District, GO
4.63%, 02/01/39		1,500		1,328,460
4.75%, 02/01/45		2,500		2,197,725
Houston Higher Education Finance Corp., RB, 6.50%, 05/15/21(d)		535		555,886
Mission Economic Development Corp., Refunding RB, AMT, Senior Lien, 4.63%, 10/01/31(a)		1,385		1,454,984

Security	Par (000)		Value
Texas (continued)
New Hope Cultural Education Facilities Finance Corp., RB
5.00%, 08/15/39(a)	$	420	$	436,892
5.00%, 08/15/49(a)		825		847,481
Series A, 5.88%, 04/01/23(d)		890		1,015,855
Series A, 6.00%, 04/01/23(d)		1,355		1,550,825
New Hope Cultural Education Facilities Finance Corp., Refunding RB(a)
Series A, 5.00%, 08/15/36		2,520		2,539,681
Series A, 5.00%, 08/15/46		695		697,829
Newark Higher Education Finance Corp., RB
5.00%, 06/15/48		1,500		1,517,055
Series A, 5.50%, 08/15/35(a)		375		420,124
Series A, 5.75%, 08/15/45(a)		735		819,782
Port Beaumont Navigation District, Refunding RB(a)
Series A, AMT, 3.63%, 01/01/35		1,665		1,608,107
Series A, AMT, 4.00%, 01/01/50		3,600		3,525,696
Red River Health Facilities Development Corp., RB
5.13%, 01/01/41		600		600,048
7.25%, 12/15/42(e)(f)		1,330		879,883
Tarrant County Cultural Education Facilities Finance Corp., RB, Series B, 5.00%, 07/01/48		8,560		10,268,747
Texas Transportation Commission, RB(c)
0.00%, 08/01/46		2,580		845,440
0.00%, 08/01/47		3,850		1,197,119
0.00%, 08/01/48		4,070		1,201,627
0.00%, 08/01/49		3,825		1,071,612
0.00%, 08/01/50		5,485		1,449,576
0.00%, 08/01/51		3,230		806,757
0.00%, 08/01/52		3,230		761,828
0.00%, 08/01/53		290		64,705
Town of Flower Mound Texas, SAB, 6.50%, 09/01/36		1,500		1,542,930
				72,621,699
Utah — 0.1%
Utah Charter School Finance Authority, Refunding RB, Series A, 6.75%, 10/15/43		2,050		2,054,469
Vermont — 0.2%
East Central Vermont Telecommunications District, RB, Series A, 4.75%, 12/01/40(a)		2,850		2,518,203
Virginia — 1.1%
Hanover County Economic Development Authority, Refunding RB, Series A, 5.00%, 07/01/47		1,015		1,017,345
Lower Magnolia Green Community Development Authority, SAB(a)
5.00%, 03/01/35		490		495,880
5.00%, 03/01/45		505		500,612
Mosaic District Community Development Authority, TA
Series A, 6.63%, 03/01/26		515		518,698
Series A, 6.88%, 03/01/36		450		452,137
Norfolk Redevelopment & Housing Authority, RB
Series A, 5.00%, 01/01/49		1,250		1,279,537
Series A, 5.25%, 01/01/54		3,750		3,891,412
Salem Economic Development Authority, Refunding RB, 4.00%, 04/01/45		830		870,438

S C H E D U L E  O F  I N V E S T M E N T  S 9

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Virginia (continued)
Virginia Beach Development Authority, Refunding RB, 4.00%, 09/01/48	$	2,885	$	2,964,107
Virginia Small Business Financing Authority, RB, AMT, Senior Lien, 6.00%, 01/01/37		3,360		3,598,694
				15,588,860
Washington — 0.4%
Greater Wenatchee Regional Events Center Public Facilities Dist, Refunding RB, Series A, 5.50%, 09/01/42		1,005		986,699
Washington Health Care Facilities Authority, Refunding RB, Series A, 4.00%, 08/01/44		885		961,039
Washington State Housing Finance Commission, Refunding RB(a)
5.75%, 01/01/35		355		372,104
6.00%, 01/01/45		940		978,427
5.00%, 01/01/48		2,410		2,523,993
				5,822,262
Wisconsin — 3.6%
Public Finance Authority, RB
5.00%, 06/15/39		310		353,571
5.00%, 06/15/41(a)		925		930,994
5.00%, 01/01/42(a)(h)		1,555		1,586,193
6.85%, 11/01/46(a)		1,325		1,393,185
7.00%, 11/01/46(a)		805		852,527
5.00%, 06/15/49		955		1,074,337
5.63%, 06/15/49(a)		6,000		6,171,240
5.00%, 04/01/50(a)		315		331,333
5.00%, 06/15/53		645		723,942
5.00%, 06/15/55(a)		2,405		2,314,163
5.00%, 01/01/56(a)(h)		3,790		3,806,524
Series A, 5.13%, 10/01/22(d)		1,850		2,031,004
Series A, 6.25%, 10/01/31(a)		910		950,632
Series A, 5.00%, 06/01/40(a)		750		748,830
Series A, 5.38%, 06/01/44(a)		1,215		1,126,985
Series A, 5.38%, 07/15/47(a)		1,595		1,663,681
Series A, 7.00%, 10/01/47(a)		910		933,387
Series A, 5.00%, 06/01/49(a)		1,340		1,284,511
Series A, 5.63%, 06/15/49(a)		8,105		7,779,989
Series A, 5.50%, 06/01/54(a)		1,500		1,383,750
Series A-1, 4.50%, 01/01/35(a)		895		897,264
Series A-1, 5.50%, 12/01/48(a)(e)(f)		38		35,276
Series A-1, 5.00%, 01/01/55(a)		2,470		2,440,607
Series B, 0.00%, 01/01/35(a)(c)		1,250		500,500
Series B, 0.00%, 01/01/60(a)(c)		17,150		1,043,235
Public Finance Authority, Refunding RB
5.00%, 03/01/52(a)		1,300		1,324,310
Series A, 5.00%, 10/01/34(a)		280		298,693
Series A, 5.00%, 10/01/39(a)		680		712,871
Series B, AMT, 5.00%, 07/01/42		2,150		2,245,911
Wisconsin Health & Educational Facilities Authority, Refunding RB
5.00%, 11/01/46		1,130		1,139,752

Security	Par (000)		Value
Wisconsin (continued)
Wisconsin Health & Educational Facilities Authority, Refunding RB (continued)
5.00%, 11/01/54	$	1,880	$	1,856,105
Wisconsin Housing & Economic Development Authority, RB, Series A, 4.70%, 07/01/47		740		804,794
				50,740,096
Total Municipal Bonds — 91.9% (Cost: $1,241,324,025)				1,289,156,366
Municipal Bonds Transferred to Tender Option Bond Trusts(j)
Georgia — 0.2%
Dalton Whitfield County Joint Development Authority, RB, 4.00%, 08/15/48		3,140		3,490,958
Illinois — 1.1%
Illinois Finance Authority, RB, Series A, (AGM), 6.00%, 08/15/41		2,480		2,587,260
Illinois Finance Authority, Refunding RB
Series C, 4.00%, 02/15/27(d)		13		13,917
Series C, 4.00%, 02/15/41		6,497		7,194,992
Illinois State Toll Highway Authority, RB, Series A, 5.00%, 01/01/40		5,011		5,805,182
				15,601,351
Maryland — 1.2%
Maryland Health & Higher Educational Facilities Authority, RB, Series B, 4.00%, 04/15/50		15,000		16,827,300
Massachusetts — 0.3%
Commonwealth of Massachusetts Transportation Fund Revenue, RB, Series A, 4.00%, 06/01/45		3,464		3,792,242
NewYork — 6.9%
Hudson Yards Infrastructure Corp., RB(k)
5.75%, 02/15/21(d)		1,065		1,085,488
5.75%, 02/15/47		655		667,759
New York City Housing Development Corp., RB
Series C-1A, 4.15%, 11/01/39		3,107		3,268,656
Series C-1A, 4.20%, 11/01/44		5,695		5,991,332
Series C-1A, 4.30%, 11/01/47		4,660		4,902,913
New York City Water & Sewer System, Refunding RB, Series HH, 5.00%, 06/15/31(k)		3,015		3,113,550
New York Liberty Development Corp., ARB, 5.25%, 12/15/43		7,725		8,088,003
New York Liberty Development Corp., Refunding RB, 5.75%, 11/15/51(k)		2,520		2,648,085
New York Power Authority, Refunding RB, Series A, 4.00%, 11/15/60		3,421		3,931,289
New York State Dormitory Authority, Refunding RB
Series D, 4.00%, 02/15/47		17,080		19,408,346
Series E, 5.00%, 03/15/36		21,670		25,451,848
New York State Urban Development Corp., RB, Series A, 4.00%, 03/15/46		13,005		14,548,564
Port Authority of New York & New Jersey, Refunding ARB, 194th Series, 5.25%, 10/15/55		2,925		3,388,145
				96,493,978

10

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
North Carolina — 0.3%
North Carolina Capital Facilities Finance Agency, Refunding RB, Series B, 5.00%, 10/01/25(d)	$	2,930	$	3,610,258
Pennsylvania — 1.2%
Pennsylvania Economic Development Financing Authority, RB, Series A-1, 4.00%, 04/15/50		11,000		12,262,027
Pennsylvania Turnpike Commission, RB, Sub- Series A, 5.50%, 12/01/42		3,677		4,393,671
				16,655,698
Rhode Island — 0.2%
Narragansett Bay Commission, Refunding RB, Series A, 4.00%, 09/01/22(d)		2,641		2,834,840
Texas — 0.3%
Lower Colorado River Authority, Refunding RB, 4.00%, 05/15/43		3,480		3,603,610
Washington — 0.9%
City of Bellingham Washington Water & Sewer Revenue, RB, 5.00%, 08/01/40		2,999		3,118,666
Snohomish County Public Utility District No.1, RB, 5.00%, 12/01/45		8,664		10,230,487
				13,349,153
Wisconsin — 0.1%
Wisconsin Health & Educational Facilities Authority, Refunding RB, 4.00%, 12/01/46		1,774		1,944,359
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 12.7% (Cost: $166,587,539)				178,203,747
Total Long-Term Investments — 104.6% (Cost: $1,407,911,564)				1,467,360,113
	Shares
Short-Term Securities
Money Market Funds — 2.6%
BlackRock Liquidity Funds, MuniCash, Institutional Class, 0.01%(l)(m)		36,963,582		36,970,974
Total Short-Term Securities — 2.6% (Cost: $36,967,432)				36,970,974
Total Investments — 107.2% (Cost: $1,444,878,996)				1,504,331,087
Other Assets Less Liabilities — 0.1%				1,182,935
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (7.3)%				(102,220,498	)
Net Assets — 100.0%			$	1,403,293,524

^(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)  Step-up bond that pays an initial coupon rate for the first period and then a higher coupon rate for the following periods. Rate as of period end.

^(c)  Zero-coupon bond.

^(d)  U.S. Government securities held in escrow, are used to pay interest on this security as well as to retire the bond in full at the date indicated, typically at a premium to par.

^(e)  Issuer filed for bankruptcy and/or is in default.

^(f)  Non-income producing security.

^(g)  Variable or floating rate security, which interest rate adjusts periodically based on changes in current interest rates and prepayments on the underlying pool of assets. Rate shown is the rate in effect as of period end.

^(h)  When-issued security.

⁽ⁱ⁾  Variable rate security. Rate shown is the rate in effect as of period end.

^(j)  Represent bonds transferred to a TOB Trust in exchange of cash and residual certificates received by the Fund. These bonds serve as collateral in a secured borrowing.

^(k)  All or a portion of the security is subject to a recourse agreement. The aggregate maximum potential amount the Fund could ultimately be required to pay under the agreements, which expire between December 15, 2020 to February 15, 2047, is $4,332,891.

^(l)  Affiliate of the Fund.

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

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Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund

Affiliates

Investments in issuers considered to be affiliate(s) of the Fund during the period ended September 30, 2020, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliated Issuer	Value at 06/30/20		Purchases at Cost		Proceeds from Sales			Net Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)			Value at 09/30/20		Shares Held at 09/30/20		Income		Capital Gain Distributions from Underlying Funds
BlackRock Liquidity Funds, MuniCash, Institutional Class	$	93,924,405	$	—	$	(56,953,431	)(a)	$	177	$	(177	)	$	36,970,974		36,963,582	$	4,928	$	—

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

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)

• Level 3 – Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the BlackRock Global Valuation Methodologies Committee’s (the “Global 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 Global 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.

The following table summarizes the Fund’s investments categorized in the disclosure hierarchy. The breakdown of the Fund’s investments 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	$	—	$	1,289,156,366	$	—	$	1,289,156,366
Municipal Bonds Transferred to Tender Option Bond Trusts		—		178,203,747		—		178,203,747
Short-Term Securities
Money Market Funds		36,970,974		—		—		36,970,974
	$	36,970,974	$	1,467,360,113	$	—	$	1,504,331,087

The Fund may hold assets and/or liabilities in which the fair value approximates the carrying amount for financial statement purposes. As of period end, TOB Trust Certificates of $102,185,837 are categorized as Level 2 within the disclosure hierarchy.

Portfolio Abbreviation
AGC	Assured Guaranty Corp.
AGM	Assured Guaranty Municipal Corp.
AMT	Alternative Minimum Tax
ARB	Airport Revenue Bonds
GO	General Obligation Bonds

Portfolio Abbreviation (continued)
GTD	GTD Guaranteed
M/F	Multi-Family
NPFGC	National Public Finance Guarantee Corp.
RB	Revenue Bond
S/F	Single-Family

12

Schedule of Investments (unaudited) (continued) September 30, 2020 BlackRock High Yield Municipal Fund

Portfolio Abbreviation (continued)
SAB	Special Assessment Bonds
ST	Special Tax
TA	Tax Allocation

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