February 28, 2026 
2026 Quarterly Report
(Unaudited)
 
BlackRock California Municipal Series Trust
• BlackRock California Municipal Opportunities Fund
 
Not FDIC Insured • May Lose Value • No Bank Guarantee
Schedule of Investments (unaudited)
February 28, 2026
BlackRock California Municipal Opportunities Fund
(Percentages shown are based on Net Assets)
 
Security
 
 
Shares
Value
Investment Companies
Fixed Income Funds — 1.0%
iShares California Muni Bond ETF(a)(b)
 
420,000
$    24,532,200
Total Investment Companies — 1.0%
(Cost: $24,532,074)
24,532,200
 
 
 
Par
(000)
 
Municipal Bonds
California — 85.3%
Corporate — 13.6%
California Community Choice Financing Authority, RB
 
Sustainability Bonds, 5.00%, 12/01/35
$
24,500
27,591,028
Sustainability Bonds, 5.50%, 10/01/54(c)
 
14,315
15,731,839
Series A, Sustainability Bonds, 5.00%, 01/01/56(c)
 
15,000
16,069,491
Series B, Class B, Sustainability Bonds, 5.00%,
03/01/56(c)
 
45,000
49,984,222
Series D, Sustainability Bonds, 5.00%, 02/01/55(c)
 
20,110
22,249,071
Series E, Sustainability Bonds, 5.00%, 10/01/56(c)
 
60,000
67,196,417
Series E-1, Sustainability Bonds, 5.00%, 02/01/54(c)
 
51,000
55,156,429
Series F, Sustainability Bonds, 5.00%, 11/01/33
 
15,000
16,599,678
Series F, Sustainability Bonds, 5.00%, 02/01/55(c)
 
27,535
30,226,078
Series G, Sustainability Bonds, 5.00%, 11/01/55(c)
 
22,460
23,672,898
California Municipal Finance Authority, RB, Series B,
AMT, 3.25%, 07/01/51(c)
 
4,450
4,452,407
California Pollution Control Financing Authority, RB(c)(d)
 
Series A-1, AMT, 3.25%, 11/01/42
 
2,250
2,250,393
Series A2, AMT, 3.25%, 11/01/42
 
2,625
2,625,458
 
 
333,805,409
County/City/Special District/School District — 26.9%
Alameda County Fire Department, GO, 06/01/50
 
2,850
3,070,228
Benicia Unified School District, GO, Series B, Election
2024, 5.00%, 08/01/51
 
2,500
2,678,978
Brea Olinda Unified School District, GO, Series A,
5.00%, 08/01/49
 
2,050
2,200,304
Butte-Glenn Community College District, GO, Series D,
Election 2016, 5.00%, 08/01/50
 
7,205
7,735,126
California Infrastructure & Economic Development
Bank, Refunding RB, Series A, 1.60%, 10/01/29
 
3,575
3,344,453
Chabot-Las Positas Community College District, GO,
Series C, Election 2016, 5.25%, 08/01/48
 
14,310
15,454,723
Chaffey Community College District, GO, Series B-1,
Election 2018, 5.50%, 06/01/49
 
7,500
8,355,287
Chaffey Joint Union High School District, GO, Series H,
Election 2012, 5.00%, 08/01/49
 
3,045
3,268,540
Chino Valley Unified School District, GO, Series D,
5.00%, 08/01/49
 
3,075
3,300,742
Citrus Community College District, GO
 
Series B, Election 2020, 5.00%, 08/01/46
 
3,840
4,187,054
Series B, Election 2020, 5.00%, 08/01/49
 
1,680
1,802,090
City of Lake Elsinore California, ST
 
5.00%, 09/01/41
 
500
535,038
5.00%, 09/01/46
 
475
493,607
5.00%, 09/01/51
 
650
661,942
5.00%, 09/01/55
 
650
659,063
City of Sacramento California Transient Occupancy Tax
Revenue, RB, Series A, 5.00%, 06/01/48
 
10,000
10,278,303
City of San Jose California, GO
 
Series A, 5.00%, 09/01/48
 
5,810
6,336,068
Security
 
Par
(000)
Value
County/City/Special District/School District (continued)
City of San Jose California, GO (continued)
 
Series A, 5.00%, 09/01/49
$
8,920
$ 9,676,278
Series A, 5.00%, 09/01/50
 
7,535
8,157,894
Series A, 5.00%, 09/01/51
 
7,705
8,320,975
City of Wildomar, ST
 
5.00%, 09/01/46
 
325
336,460
5.00%, 09/01/51
 
600
610,105
5.00%, 09/01/55
 
550
558,507
Clovis Unified School District, GO, Series A, Election
2024, 5.00%, 08/01/50
 
4,665
4,921,260
Coast Community College District, GO, Series B,
Election 2002, (AGM), 0.00%, 08/01/30(e)
 
26,425
23,855,885
Cupertino Union School District, GO, Series A, Election
2024, 5.75%, 08/01/50
 
4,840
5,543,109
Del Mar Union School District, GO, Series B, Election
2018, 4.00%, 08/01/46
 
4,280
4,332,173
Desert Community College District, GO, Election 2016,
5.00%, 08/01/51
 
13,275
14,279,140
Foothill-De Anza Community College District, GO
 
Series D, Election 2020, 5.00%, 08/01/43
 
3,000
3,429,117
Series D, Election 2020, 5.00%, 08/01/44
 
3,150
3,548,853
Series D, Election 2020, 5.00%, 08/01/45
 
3,000
3,337,043
Fremont Unified School District/Alameda County
California, GO, Series A, Election 2024, 5.25%,
08/01/43
 
7,565
8,556,772
Fremont Union High School District, GO, Election
2022, 4.00%, 08/01/48
 
22,500
22,445,876
Glendale Community College District, GO, Series A,
Election 2024, 5.00%, 08/01/50
 
2,500
2,675,859
Los Angeles County Metropolitan Transportation
Authority Sales Tax Revenue, RB, Series A, 5.00%,
07/01/42
 
8,945
9,907,667
Los Angeles County Public Works Financing Authority
Refunding RB, Series H, 5.50%, 12/01/49
 
6,500
7,243,285
Los Gatos Union School District, GO, Election 2024,
5.00%, 08/01/52
 
12,275
13,072,179
Lucia Mar Unified School District, GO
 
Series D, Election 2016, 5.25%, 08/01/47
 
9,275
9,921,655
Series A, Election 2024, 08/01/51(f)
 
1,500
1,616,530
Maryland Community Development Administration, RB,
S/F Housing, Series B, Sustainability Bonds,
(FHLMC, FNMA, GNMA), 5.00%, 08/01/52
 
5,985
6,399,759
Modesto High School District, GO, Series B, Election
2022, 5.25%, 08/01/50
 
3,325
3,656,022
Mt San Antonio Community College District, GO,
Series A, Election 2024, 5.00%, 08/01/50
 
23,095
25,001,063
Salinas Union High School District, GO, Series B,
Election 2020, 5.00%, 08/01/48
 
9,410
10,155,436
San Bernardino Community College District, GO,
Series B, Election 2018, 5.00%, 08/01/49
 
14,000
14,748,219
San Diego Public Facilities Financing Authority,
Refunding RB
 
Series A, 5.00%, 10/15/47
 
15,000
16,272,397
Series A, 5.00%, 10/15/49
 
1,810
1,934,679
Series A, 5.00%, 10/15/50
 
24,035
25,676,788
San Diego Unified School District, GO
 
Series I, Election 2012, 5.00%, 07/01/47
 
4,750
4,839,638
Series C-3, Election 2022, 5.00%, 07/01/50
 
24,420
26,222,782
Series A-3, Sustainability Bonds, 5.00%, 07/01/48
 
14,500
15,534,202
Series N2, Sustainability Bonds, 5.00%, 07/01/48
 
5,990
6,417,233
2
Schedule of Investments (unaudited)(continued)
February 28, 2026
BlackRock California Municipal Opportunities Fund
(Percentages shown are based on Net Assets)
Security
 
Par
(000)
Value
County/City/Special District/School District (continued)
San Francisco Bay Area Rapid Transit District, GO
 
Series A, Election 2016, Sustainability Bonds,
5.00%, 08/01/47
$
4,000
$ 4,071,537
Series D1, Sustainability Bonds, 5.25%, 08/01/47
 
11,805
12,698,535
San Francisco City & County Public Utilities
Commission Wastewater Revenue, RB, Series B,
Sustainability Bonds, 1.00%, 10/01/26(g)
 
27,880
27,737,787
San Jose Unified School District, GO, Series C,
Election 2002, (NPFGC), 0.00%, 06/01/31(e)
 
25,000
22,153,862
San Leandro Unified School District, GO, Series B,
5.25%, 08/01/48
 
8,335
9,001,060
San Luis Coastal Unified School District, GO, Series B,
Election 2022, 5.00%, 08/01/50
 
5,825
6,144,171
San Luis Obispo County Financing Authority,
Refunding RB, 5.50%, 11/15/47
 
5,165
5,672,960
San Marcos Unified School District, GO, Series A,
Election 2024, 5.25%, 08/01/50
 
13,250
14,460,324
San Mateo County Community College District, GO,
Series B, Election 2014, 5.00%, 09/01/45
 
24,000
24,942,732
San Mateo Foster City Public Financing Authority, RB,
4.00%, 05/01/45
 
4,000
4,006,155
San Mateo Foster City School District, GO
 
Series C, Election 2020, 5.00%, 08/01/43
 
2,380
2,655,032
Series C, Election 2020, 5.00%, 08/01/51
 
11,500
12,194,255
Santa Clara County Financing Authority, RB, Series A,
4.00%, 05/01/45
 
10,000
9,968,973
Santa Clarita Community College District, GO, Election
2016, 5.25%, 08/01/48
 
8,545
9,182,592
Santa Rosa High School District, GO, Series B, 5.25%,
08/01/50
 
8,265
8,995,640
Solano County Community College District, GO,
Series G, Election 2012, 5.00%, 08/01/50
 
6,330
6,816,291
Tamalpais Union High School District, GO
 
Series A, Election 2024, 4.00%, 08/01/46
 
13,420
13,607,812
Series A, Election 2024, 4.00%, 08/01/47
 
10,000
10,093,998
Series A, Election 2024, 4.00%, 08/01/48
 
7,965
8,012,243
Series A, Election 2024, 4.13%, 08/01/49
 
9,490
9,586,900
Series A, Election 2024, 4.13%, 08/01/50
 
12,000
12,087,010
Tracy Unified School District School Facilities
Improvement District No 3, GO, Series A, Election
2024, 5.00%, 08/01/50
 
2,635
2,835,288
Victor Valley Union High School District, GO, Series A,
Election 2024, 5.25%, 08/01/50
 
4,500
4,867,154
West Valley-Mission Community College District, GO
 
Series A, 4.00%, 08/01/44
 
8,345
8,374,230
Series B, 4.00%, 08/01/47
 
15,000
15,035,239
 
 
662,768,166
Education — 5.7%
California Infrastructure & Economic Development
Bank, RB, CAB, 0.00%, 01/01/60(e)
 
37,500
3,539,055
California Municipal Finance Authority, RB, 4.65%,
05/01/30
 
400
414,628
California Municipal Finance Authority, Refunding
RB(d)(h)(i)
 
5.00%, 08/01/39
 
835
628,893
5.00%, 08/01/48
 
1,795
1,197,849
California Public Finance Authority, RB, Series B,
5.00%, 07/01/26(d)
 
40
39,881
California School Finance Authority, RB, Series A,
6.00%, 07/01/51(d)
 
1,500
1,504,456
Security
 
Par
(000)
Value
Education (continued)
California School Finance Authority, Refunding RB,
Series A, 4.75%, 06/01/44(d)
$
810
$ 806,627
California State University, RB, Series A, 5.25%,
11/01/48
 
4,535
4,955,109
California State University, Refunding RB
 
Series A, 5.00%, 11/01/43
 
18,000
18,845,755
Series A, 5.25%, 11/01/50
 
32,000
35,335,846
Series B, 1.67%, 11/01/29
 
9,000
8,390,794
Series B, 1.85%, 11/01/31
 
6,750
6,066,578
Series D, 1.69%, 11/01/29
 
5,000
4,664,270
University of California, RB(f)
 
Series CE, 11/15/39
 
6,000
7,355,657
Series CE, 11/15/41
 
20,000
23,245,640
Series CF, 11/15/41
 
20,000
23,736,184
 
 
140,727,222
Health — 3.7%
California Health Facilities Financing Authority,
Refunding RB
 
Series A, 5.25%, 08/15/50
 
2,995
3,250,458
Series A-2, Class B, (BAM-TCRS), 4.00%, 11/01/44
 
4,000
3,932,657
Series B, 5.00%, 11/15/46
 
9,965
10,058,806
California Public Finance Authority, RB
 
Series A, 6.20%, 06/01/44(d)
 
11,380
11,412,062
Series A, 5.00%, 07/15/46
 
8,580
9,156,280
Series A, 6.50%, 06/01/54(d)
 
3,000
2,926,995
Series B, 8.25%, 06/01/33
 
12,930
13,487,817
California Public Finance Authority, Refunding RB,
Series A, 5.00%, 08/01/47
 
6,000
6,107,710
Regents of the University of California Medical Center
Pooled Revenue, RB, Series P, 5.00%, 05/15/47
 
28,130
29,902,511
 
 
90,235,296
Housing — 1.5%
California Housing Finance Agency, RB, M/F Housing
 
Subordinate, 8.00%, 12/01/56(c)
 
3,045
3,060,742
Series P-S, Subordinate, 8.00%, 07/01/67(c)(d)
 
5,395
5,491,810
Series A, Sustainability Bonds, 4.75%, 08/01/45
 
13,000
13,569,817
California Municipal Finance Authority, RB, M/F
Housing
 
6.00%, 02/01/38(c)
 
6,100
6,147,612
Series A, 6.10%, 12/01/37
 
6,000
6,162,521
Series A-S, Subordinate, 8.13%, 08/01/56(c)(d)
 
1,000
1,008,439
CSCDA Community Improvement Authority, RB, M/F
Housing, Sustainability Bonds, 4.00%, 07/01/58(d)
 
1,205
736,880
 
 
36,177,821
State — 3.4%
California State Public Works Board, RB
 
Series A, 5.00%, 04/01/49
 
42,215
45,188,726
Series A, 5.00%, 04/01/50
 
10,000
10,708,700
Series C, 5.00%, 11/01/50
 
5,000
5,372,895
State of California, GO, Class C, 5.00%, 11/01/50
 
5,000
5,382,280
State of California, Refunding GO
 
5.50%, 08/01/49
 
5,750
6,429,739
Class B, 5.10%, 09/01/35
 
10,000
10,592,438
 
 
83,674,778
Tobacco — 2.4%
California County Tobacco Securitization Agency,
Refunding RB, Series A, 5.00%, 06/01/47
 
2,595
2,482,851
California County Tobacco Securitization Agency,
Refunding RB, CAB, Series B-2, Subordinate,
0.00%, 06/01/55(e)
 
7,620
1,476,790
Schedule of Investments
3
Schedule of Investments (unaudited)(continued)
February 28, 2026
BlackRock California Municipal Opportunities Fund
(Percentages shown are based on Net Assets)
Security
 
Par
(000)
Value
Tobacco (continued)
California Statewide Financing Authority, RB(d)(e)
 
Series D, 0.00%, 06/01/55
$
20,750
$ 1,279,700
Series L, 0.00%, 06/01/55
 
91,500
5,710,936
Golden State Tobacco Securitization Corp., Refunding
RB
 
Class B, (SAP), 3.29%, 06/01/42
 
3,105
2,483,173
Series A-1, 3.71%, 06/01/41
 
4,135
3,348,680
Series A-1, Class A1, 3.49%, 06/01/36
 
1,310
1,144,890
Series B, 5.00%, 06/01/51
 
18,440
18,336,214
Golden State Tobacco Securitization Corp., Refunding
RB, CAB, Series B-2, Subordinate, 0.00%,
06/01/66(e)
 
104,805
11,173,838
Inland Empire Tobacco Securitization Corp., RB,
0.00%, 06/01/57(e)
 
34,680
2,758,454
Tobacco Securitization Authority of Southern California,
Refunding RB, 5.00%, 06/01/48
 
8,055
8,147,747
 
 
58,343,273
Transportation — 16.2%
Burbank-Glendale-Pasadena Airport Authority Brick
Campaign, ARB
 
Series B, 5.56%, 07/01/32
 
755
793,987
Series B, AMT, 5.25%, 07/01/49
 
11,875
12,587,323
California Infrastructure & Economic Development
Bank, RB, Class C, AMT, 3.50%, 01/01/65(c)(d)
 
12,000
12,004,039
California Infrastructure & Economic Development
Bank, Refunding RB, Class B, AMT, Sustainability
Bonds, 12.00%, 01/01/65(c)(d)
 
50,020
27,010,800
City of Los Angeles Department of Airports, ARB
 
Series A, AMT, 5.00%, 05/15/42
 
10,000
10,154,186
AMT, Sustainability Bonds, 5.25%, 05/15/47
 
23,500
24,666,796
Series E, Subordinate, 5.00%, 05/15/50
 
8,950
9,605,332
City of Los Angeles Department of Airports, Refunding
ARB
 
AMT, 5.50%, 05/15/47
 
7,000
7,446,244
AMT, Subordinate, 5.00%, 05/15/35
 
5,425
5,789,275
City of Los Angeles Department of Airports, Refunding
RB
 
Class D, Subordinate, 5.00%, 05/15/48
 
26,500
28,735,999
Series D, Subordinate, 5.25%, 05/15/48
 
2,545
2,829,340
Series D, Subordinate, 5.25%, 05/15/51
 
23,810
25,941,059
County of Sacramento California Airport System
Revenue, ARB
 
5.00%, 07/01/49
 
5,155
5,493,626
5.25%, 07/01/49
 
35,365
38,359,609
San Diego County Regional Airport Authority, ARB
 
AMT, 5.50%, 07/01/55
 
2,500
2,688,499
Series B, AMT, 5.00%, 07/01/47
 
2,250
2,264,267
Series B, AMT, 5.00%, 07/01/48
 
16,790
17,425,859
Series B, AMT, 5.25%, 07/01/50
 
18,790
19,869,585
Series B, AMT, Subordinate, 5.00%, 07/01/51
 
6,500
6,601,858
San Francisco City & County Airport Comm-San
Francisco International Airport, Refunding ARB
 
Series 2, Class A, AMT, 5.25%, 05/01/49
 
7,400
7,831,281
Series A, AMT, 5.00%, 05/01/38
 
10,350
10,923,360
Series A, AMT, 5.00%, 05/01/47
 
35,700
35,950,889
Series A, AMT, 5.50%, 05/01/55
 
3,220
3,464,285
Series B, AMT, 5.00%, 05/01/46
 
36,820
36,859,158
Series D, AMT, 5.00%, 05/01/43
 
16,440
16,868,430
Security
 
Par
(000)
Value
Transportation (continued)
San Francisco City & County Airport Comm-San
Francisco International Airport, Refunding
ARB (continued)
 
Series D, AMT, 5.25%, 05/01/48
$
3,900
$ 3,971,565
Series E, AMT, 5.00%, 05/01/37
 
4,000
4,237,345
San Francisco City & County Airport Comm-San
Francisco International Airport, Refunding RB,
Series D, AMT, 5.50%, 05/01/55
 
17,245
18,553,292
 
 
398,927,288
Utilities — 11.9%
City of Los Angeles California Wastewater System
Revenue, Refunding RB
 
Series A, 5.00%, 06/01/44
 
10,000
11,306,161
Series A, Subordinate, 5.25%, 06/01/50
 
17,040
18,752,612
City of Modesto California Wastewater Revenue, RB,
5.00%, 11/01/50
 
6,975
7,487,687
City of San Francisco CA Public Utilities Commission
Water Revenue Refunding RB, Series E, 5.25%,
11/01/55
 
15,000
16,334,886
City of San Francisco California Public Utilities
Commission Water Revenue, Refunding RB
 
5.25%, 11/01/48
 
5,505
6,041,782
Class D, 5.00%, 11/01/51
 
30,775
33,101,916
East Bay Municipal Utility District Water System
Revenue, RB
 
Series A, Sustainability Bonds, 5.00%, 06/01/42
 
11,000
11,269,867
Series A, Sustainability Bonds, 5.00%, 06/01/49
 
15,000
16,123,151
Series A, Sustainability Bonds, 5.00%, 06/01/50
 
20,000
21,658,080
Series A, Sustainability Bonds, 06/01/55(f)
 
12,600
13,511,408
Series A, Sustainability Bonds, 5.00%, 06/01/55
 
1,140
1,222,461
East Bay Municipal Utility District Water System
Revenue, Refunding RB, Series B, 5.00%, 06/01/43
 
4,505
5,193,985
Imperial Irrigation District Electric System Revenue,
Refunding RB, 5.00%, 11/01/50
 
7,275
7,809,738
Metropolitan Water District of Southern California,
Refunding RB
 
Series A, 5.00%, 04/01/48
 
7,095
7,602,495
Series A, 5.00%, 10/01/49
 
5,000
5,179,843
Modesto Irrigation District, RB
 
Series A, 5.25%, 10/01/43
 
6,605
7,467,798
Series A, 5.25%, 10/01/48
 
5,055
5,495,666
Sacramento County Water Financing Authority, RB,
5.00%, 06/01/50
 
9,005
9,600,371
Sacramento Municipal Utility District, Refunding RB,
Series H, Sustainability Bonds, 5.00%, 08/15/50
 
20,000
20,806,602
San Diego Public Facilities Financing Authority, RB
 
Series A, 5.00%, 05/15/49
 
3,390
3,650,713
Series A, Subordinate, 5.00%, 05/15/47
 
6,625
7,108,789
San Diego Public Facilities Financing Authority,
Refunding RB
 
Series A, 5.25%, 08/01/48
 
8,385
9,196,655
Series A, Subordinate, 5.00%, 08/01/43
 
1,000
1,044,175
San Francisco City & County Public Utilities
Commission Wastewater Revenue, RB, Series A,
Sustainability Bonds, 4.66%, 10/01/27
 
16,710
16,971,112
San Francisco City & County Public Utilities
Commission Wastewater Revenue, Refunding RB,
Series C, Sustainability Bonds, 5.00%, 10/01/49
 
5,550
6,001,989
4
Schedule of Investments (unaudited)(continued)
February 28, 2026
BlackRock California Municipal Opportunities Fund
(Percentages shown are based on Net Assets)
Security
 
Par
(000)
Value
Utilities (continued)
San Jose Financing Authority, Refunding RB, Series B,
Sustainability Bonds, 5.00%, 11/01/47
$
2,000
 $ 2,148,602
State of California Department of Water Resources.
Refunding RB, Series A, 5.00%, 12/01/51
 
20,350
22,035,821
 
 
294,124,365
Total Municipal Bonds in California
2,098,783,618
District of Columbia — 0.0%
Tobacco — 0.0%
District of Columbia Tobacco Settlement Financing
Corp., RB, Series A, 0.00%, 06/15/46(e)
 
2,125
511,013
Florida(c)(d)(h)(i) — 0.2%
Transportation — 0.2%
Florida Development Finance Corp., RB, Series A,
AMT, 12.00%, 07/15/59
 
6,470
2,264,500
Florida Development Finance Corp., Refunding RB,
AMT, 12.00%, 07/15/32
 
4,785
1,674,750
Total Municipal Bonds in Florida
3,939,250
Ohio — 0.3%
Tobacco — 0.3%
Buckeye Tobacco Settlement Financing Authority,
Refunding RB, Series B-2, Class 2, 5.00%,
06/01/55
 
9,130
7,538,769
Puerto Rico — 4.8%
State — 3.2%
Commonwealth of Puerto Rico, GO
 
Series A-1, Restructured, 5.63%, 07/01/29
 
829
885,409
Series A-1, Restructured, 5.75%, 07/01/31
 
805
894,178
Series A-1, Restructured, 4.00%, 07/01/35
 
1,723
1,751,113
Series A-1, Restructured, 4.00%, 07/01/37
 
1,479
1,480,614
Series A-1, Restructured, 4.00%, 07/01/41
 
431
417,957
Series A-1, Restructured, 4.00%, 07/01/46
 
2,091
1,885,131
Commonwealth of Puerto Rico, GO, CAB, Series A,
Restructured, 0.00%, 07/01/33(e)
 
2,467
1,823,687
Commonwealth of Puerto Rico, Notes(c)
 
0.00%, 11/01/51(h)(i)
 
34,472
21,286,398
0.00%, 11/01/51
 
20,857
6,622,097
Puerto Rico Sales Tax Financing Corp., Sales Tax
Revenue, RB
 
Series A-1, Restructured, 4.75%, 07/01/53
 
15,728
15,305,601
Series A-2, Restructured, 4.54%, 07/01/53
 
114
106,745
Series A-2, Restructured, 4.78%, 07/01/58
 
12,102
11,700,300
Puerto Rico Sales Tax Financing Corp., Sales Tax
Revenue, RB, CAB(e)
 
Series A-1, Restructured, 0.00%, 07/01/29
 
1,117
1,006,302
Series A-1, Restructured, 0.00%, 07/01/33
 
3,239
2,513,239
Series A-1, Restructured, 0.00%, 07/01/46
 
23,633
8,458,043
Series B-1, Restructured, 0.00%, 07/01/46
 
5,761
2,061,811
 
 
78,198,625
Tobacco — 0.2%
Children’s Trust Fund, RB, Series A, 0.00%,
05/15/57(e)
 
89,730
4,405,609
Utilities(h)(i) — 1.4%
Puerto Rico Electric Power Authority, RB
 
Series A, 6.75%, 07/01/36
 
7,630
5,083,487
Security
 
Par
(000)
Value
Utilities (continued)
Puerto Rico Electric Power Authority, RB (continued)
 
Series A-3, 10.00%, 07/01/19
$
2,137
$ 1,426,122
Series B-3, 10.00%, 07/01/19
 
2,137
1,426,122
Series C-1, 5.40%, 01/01/18
 
5,870
3,918,190
Series C-2, 5.40%, 07/01/18
 
5,871
3,918,824
Series C-3, 5.40%, 01/01/20
 
593
396,129
Series C-4, 5.40%, 07/01/20
 
593
396,129
Series CCC, 5.25%, 07/01/28
 
955
636,269
Series D-4, 7.50%, 07/01/20
 
4,342
2,898,474
Series TT, 5.00%, 07/01/26
 
1,285
856,131
Series WW, 5.50%, 07/01/17
 
1,315
877,762
Series WW, 5.50%, 07/01/18
 
1,155
770,962
Series WW, 5.50%, 07/01/19
 
935
624,113
Series WW, 5.38%, 07/01/24
 
875
584,063
Series WW, 5.25%, 07/01/33
 
885
589,631
Series WW, 5.50%, 07/01/38
 
1,170
779,512
Series XX, 5.25%, 07/01/17
 
645
429,731
Series XX, 5.25%, 07/01/35
 
400
266,500
Series XX, 5.75%, 07/01/36
 
555
369,769
Series XX, 5.25%, 07/01/40
 
745
496,356
Puerto Rico Electric Power Authority, Refunding RB
 
Series AAA, 5.25%, 07/01/27
 
3,150
2,098,687
Series AAA, 5.25%, 07/01/29
 
530
353,113
Series UU, 0.00%, 07/01/17(c)
 
395
263,663
Series UU, 0.00%, 07/01/18(c)
 
355
236,963
Series UU, 1.00%, 07/01/31(c)
 
2,765
1,842,181
Series YY, 6.13%, 07/01/40
 
4,060
2,704,975
Series ZZ, 5.00%, 07/01/28
 
990
659,588
Series ZZ, 5.00%, 12/29/49
 
925
617,438
 
 
35,520,884
Total Municipal Bonds in Puerto Rico
118,125,118
Wisconsin — 0.4%
Transportation — 0.4%
Public Finance Authority, RB, Series A, AMT, Senior
Lien, 5.75%, 07/01/49
 
10,245
10,808,367
Total Municipal Bonds — 91.0%
(Cost: $2,235,065,375)
2,239,706,135
 
 
 
 
Shares
 
Warrants
Construction & Engineering — 0.0%
Brightline West, (Expires 11/26/35, Strike Price USD
5.00)(i)(j)
 
416,612
833,224
Total Warrants — 0.0%
(Cost: $  — )
833,224
Total Long-Term Investments — 92.0%
(Cost: $2,259,597,449)
2,265,071,559
Schedule of Investments
5
Schedule of Investments (unaudited)(continued)
February 28, 2026
BlackRock California Municipal Opportunities Fund
(Percentages shown are based on Net Assets)
Security
 
 
Shares
Value
Short-Term Securities
Money Market Funds — 2.5%
BlackRock Liquidity Funds, MuniCash, Institutional
Shares, 1.72%(a)(b)
 
60,605,948
$    60,612,009
 
 
 
Par
(000)
 
U.S. Treasury Obligations — 8.1%
U.S. Treasury Bills, 3.66%, 03/10/26(k)
$
200,000
199,838,814
Total Short-Term Securities — 10.6%
(Cost: $260,431,640)
260,450,823
Total Investments — 102.6%
(Cost: $2,520,029,089)
2,525,522,382
Liabilities in Excess of Other Assets — (2.6)%
(63,578,226
)
Net Assets — 100.0%
$ 2,461,944,156
 
(a)
Affiliate of the Fund.
(b)
Annualized 7-day yield as of period end.
(c)
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.
(d)
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.
(e)
Zero-coupon bond.
(f)
When-issued security.
(g)
Security is collateralized by municipal bonds or U.S. Treasury obligations.
(h)
Issuer filed for bankruptcy and/or is in default.
(i)
Non-income producing security.
(j)
Security is valued using significant unobservable inputs and is classified as Level 3 in the
fair value hierarchy.
(k)
Rates are discount rates or a range of discount rates as of period end.
For purposes of this report, industry and sector sub-classifications may differ from those utilized by the Fund for compliance purposes. 
Affiliates
Investments in issuers considered to be affiliate(s) of the Fund during the period ended February 28, 2026 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows: 
Affiliated Issuer
Value at
05/31/25
Purchases
at Cost
Proceeds
from Sales
Net
Realized
Gain (Loss)
Change in
Unrealized
Appreciation
(Depreciation)
Value at
02/28/26
Shares
Held at
02/28/26
Income
Capital Gain
Distributions
from
Underlying
Funds
BlackRock Liquidity Funds, MuniCash, Institutional
Shares
$ 186,656,608
$ —
$ (126,044,599
)(a)
$ —
$ —
$ 60,612,009
60,605,948
$ 1,526,262
$ —
iShares California Muni Bond ETF
—
24,532,074
—
—
126
24,532,200
420,000
—
—
 
$ —
$ 126
$ 85,144,209
$ 1,526,262
$ —
 
(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 at the measurement date. 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 that the Fund has the ability to access for identical assets or liabilities;
• Level 2 – Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly; and
• Level 3 – Inputs that are unobservable and significant to the  entire fair value measurement for the asset or liability (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 that may not have a secondary market and/or may have a limited number of investors. The categorization of a value determined for financial instruments is based on the
6
Schedule of Investments (unaudited)(continued)
February 28, 2026
BlackRock California Municipal Opportunities Fund
 
Fair Value Hierarchy as of Period End (continued)
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 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 
Investment Companies
$ 24,532,200
$ —
$ —
$ 24,532,200
Municipal Bonds
—
2,239,706,135
—
2,239,706,135
Warrants
—
—
833,224
833,224
Short-Term Securities 
Money Market Funds
60,612,009
—
—
60,612,009
U.S. Treasury Obligations
—
199,838,814
—
199,838,814
 
$85,144,209
$2,439,544,949
$833,224
$2,525,522,382
 
Portfolio Abbreviation 
AGM
 Assured Guaranty Municipal Corp.
AMT
 Alternative Minimum Tax
ARB
 Airport Revenue Bonds
BAM-TCRS
 Build America Mutual Assurance Co. - Transferable
Custodial Receipts
CAB
 Capital Appreciation Bonds
ETF
 Exchange-Traded Fund
FHLMC
 Federal Home Loan Mortgage Corp.
FNMA
 Federal National Mortgage Association
GNMA
 Government National Mortgage Association
GO
 General Obligation Bonds
M/F
 Multi-Family
MT
 Mandatory Tender
NPFGC
 National Public Finance Guarantee Corp.
RB
 Revenue Bonds
S/F
 Single-Family
SAP
 Subject to Appropriations
ST
 Special Tax
Schedule of Investments
7