Managed Account Series II NPORT-P BlackRock U.S. Mortgage Portfolio (Jan 2024 report)

Schedule

of

Investments

(unaudited)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

2

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

510

Loan

Acquisition

Trust,

Series

2020-1,

Class

A,

8.11%,

09/25/60

(a)

(b)

..........

USD

968

$

962,213

Ajax

Mortgage

Loan

Trust

(b)

Series

2020-C,

Class

A,

2.25%,

09/27/60

(a)

20

19,747

Series

2020-C,

Class

B,

5.00%,

09/27/60

(a)

150

146,969

Series

2020-C,

Class

C,

0.00%,

09/27/60

.

470

390,809

Series

2020-D,

Class

A,

2.25%,

06/25/60

(a)

248

245,198

Series

2020-D,

Class

B,

5.00%,

06/25/60

(a)

210

205,868

Series

2020-D,

Class

C,

0.00%,

06/25/60

.

495

376,604

Series

2021-E,

Class

B3,

3.95%,

12/25/60

(c)

381

115,126

Series

2021-E,

Class

XS,

0.00%,

12/25/60

(c)

5,250

209,731

Series

2021-F,

Class

A,

1.87%,

06/25/61

(a)

.

2,250

2,152,695

Series

2021-F,

Class

B,

3.75%,

06/25/61

(a)

.

216

198,422

Series

2021-F,

Class

C,

0.00%,

06/25/61

..

400

321,017

Series

2021-G,

Class

A,

1.87%,

06/25/61

(c)

1,569

1,501,021

Series

2021-G,

Class

B,

3.75%,

06/25/61

(c)

256

238,579

Series

2021-G,

Class

C,

0.00%,

06/25/61

.

461

395,339

AMSR

Trust

(b)

Series

2020-SFR4,

Class

G2,

4.87%,

11/17/37

.....................

850

812,301

Series

2023-SFR2,

Class

F1,

3.95%,

06/17/40

(d)

....................

600

496,283

AREIT

LLC,

Series

2023-CRE8,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.11%

Floor

+

2.11%),

7.45%,

08/17/41

(b)

(c)

..........

552

548,006

AREIT

Trust

(b)(c)

Series

2021-CRE5,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.08%

Floor

+

1.19%),

6.53%,

11/17/38

................

475

470,301

Series

2022-CRE6,

Class

A,

(SOFR

30

day

Average

at

1.25%

Floor

+

1.25%),

6.60%,

01/20/37

.....................

581

573,884

Bayview

Financial

Revolving

Asset

Trust,

Series

2004-B,

Class

A1,

(1-mo.

CME

Term

SOFR

at

1.00%

Floor

+

1.11%),

6.45%,

05/28/39

(b)

(c)

.....................

1,746

1,380,405

BDS

Ltd.,

Series

2021-FL9,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.07%

Floor

+

1.18%),

6.52%,

11/16/38

(b)

(c)

................

607

591,612

Bear

Stearns

Asset-Backed

Securities

I

Trust

(c)

Series

2006-HE8,

Class

1A3,

(1-mo.

CME

Term

SOFR

at

0.52%

Floor

+

0.63%),

5.97%,

10/25/36

................

1,200

1,073,768

Series

2007-HE2,

Class

1A4,

(1-mo.

CME

Term

SOFR

at

0.32%

Floor

+

0.43%),

5.77%,

03/25/37

................

854

735,361

Series

2007-HE2,

Class

22A,

(1-mo.

CME

Term

SOFR

at

0.14%

Floor

+

0.25%),

5.59%,

03/25/37

................

495

449,885

BSPRT

Issuer

Ltd.,

Series

2022-FL8,

Class

A,

(SOFR

30

day

Average

at

1.50%

Floor

+

1.50%),

6.85%,

02/15/37

(b)

(c)

..........

730

721,274

Carrington

Mortgage

Loan

Trust,

Series

2007-

FRE1,

Class

M1,

(1-mo.

CME

Term

SOFR

at

0.50%

Floor

and

14.50%

Cap

+

0.61%),

5.95%,

02/25/37

(c)

.................

1,816

1,351,314

Countrywide

Asset-Backed

Certificates,

Series

2002-BC3,

Class

M2,

(1-mo.

CME

Term

SOFR

at

1.73%

Floor

+

1.84%),

7.18%,

05/25/32

(c)

......................

1,043

1,024,968

Credit-Based

Asset

Servicing

&

Securitization

LLC,

Series

2007-CB6,

Class

A4,

(1-mo.

CME

Term

SOFR

at

0.34%

Floor

+

0.45%),

5.79%,

07/25/37

(b)

(c)

................

1,483

937,598

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

(continued)

CWABS

Asset-Backed

Certificates

Trust

(c)

Series

2006-18,

Class

M1,

(1-mo.

CME

Term

SOFR

at

0.45%

Floor

+

0.56%),

5.90%,

03/25/37

.....................

USD

1,551

$

1,192,541

Series

2006-22,

Class

M1,

(1-mo.

CME

Term

SOFR

at

0.23%

Floor

+

0.34%),

5.68%,

05/25/47

.....................

2,136

1,714,042

Series

2007-BC3,

Class

1A,

(1-mo.

CME

Term

SOFR

at

0.18%

Floor

+

0.29%),

5.63%,

11/25/47

................

632

598,185

CWABS,

Inc.

Asset-Backed

Certificates

Trust,

Series

2004-6,

Class

2A4,

(1-mo.

CME

Term

SOFR

at

0.90%

Floor

+

1.01%),

6.35%,

11/25/34

(c)

.......................

8

7,491

Dryden

XXVIII

Senior

Loan

Fund,

Series

2013-28A,

Class

A1LR,

(3-mo.

CME

Term

SOFR

at

1.20%

Floor

+

1.46%),

6.85%,

08/15/30

(b)

(c)

.....................

879

879,954

FS

Rialto

Issuer

LLC

(b)(c)

Series

2022-FL6,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.58%

Floor

+

2.58%),

7.92%,

08/17/37

.....................

350

350,652

Series

2022-FL7,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.90%

Floor

+

2.90%),

8.23%,

10/19/39

.....................

540

542,829

GITSIT

Mortgage

Loan

Trust,

Series

2023-

NPL1,

Class

A1,

8.35%,

05/25/53

(a)

(b)

....

601

605,007

GSAA

Home

Equity

Trust,

Series

2006-5,

Class

1A1,

(1-mo.

CME

Term

SOFR

at

0.36%

Floor

+

0.47%),

5.81%,

03/25/36

(c)

......

97

29,647

Home

Partners

of

America

Trust,

Series

2021-3,

Class

F,

4.24%,

01/17/41

(b)

...........

1,834

1,573,229

KREF

Ltd.,

Series

2022-FL3,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.45%

Floor

+

1.45%),

6.79%,

02/17/39

(b)

(c)

................

2,950

2,914,969

Legacy

Mortgage

Asset

Trust,

Series

2019-SL2,

Class

A,

3.38%,

02/25/59

(b)

(c)

..........

1,000

953,911

Long

Beach

Mortgage

Loan

Trust

(c)

Series

2006-1,

Class

2A4,

(1-mo.

CME

Term

SOFR

at

0.60%

Floor

+

0.71%),

6.05%,

02/25/36

.....................

636

505,922

Series

2006-7,

Class

2A3,

(1-mo.

CME

Term

SOFR

at

0.32%

Floor

+

0.43%),

5.77%,

08/25/36

.....................

1,584

615,516

MF1

Multifamily

Housing

Mortgage

Loan

Trust,

Series

2024-FL14,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.74%

Floor

+

1.74%),

0.00%,

03/19/39

(b)

(c)

................

318

317,205

Morgan

Stanley

IXIS

Real

Estate

Capital

Trust,

Series

2006-1,

Class

A3,

(1-mo.

CME

Term

SOFR

at

0.30%

Floor

+

0.41%),

5.75%,

07/25/36

(c)

......................

411

161,898

Mosaic

Solar

Loan

Trust,

Series

2019-2A,

Class

A,

2.88%,

09/20/40

(b)

...............

39

34,613

New

Residential

Mortgage

Loan

Trust,

Series

2022-SFR1,

Class

F,

4.44%,

02/17/39

(b)

...

2,739

2,402,876

Option

One

Mortgage

Loan

Trust,

Series

2007-

FXD1,

Class

2A1,

5.87%,

01/25/37

(a)

.....

974

813,688

Progress

Residential

Trust

(b)

Series

2020-SFR3,

Class

G,

4.11%,

10/17/27

.....................

2,750

2,606,289

Series

2021-SFR10,

Class

F,

4.61%,

12/17/40

.....................

1,488

1,300,946

Series

2021-SFR11,

Class

F,

4.42%,

01/17/39

.....................

2,000

1,722,642

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

3

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

(continued)

Series

2022-SFR1,

Class

F,

4.88%,

02/17/41

.....................

USD

2,500

$

2,186,745

Series

2023-SFR1,

Class

E1,

6.15%,

03/17/40

.....................

925

907,732

RASC

Series

Trust,

Series

2006-EMX9,

Class

1A4,

(1-mo.

CME

Term

SOFR

at

0.24%

Floor

and

14.00%

Cap

+

0.35%),

5.93%,

11/25/36

(c)

.......................

1,172

937,477

Securitized

Asset-Backed

Receivables

LLC

Trust,

Series

2007-BR1,

Class

A2B,

(1-mo.

CME

Term

SOFR

at

0.54%

Floor

+

0.65%),

5.99%,

02/25/37

(c)

.................

1,948

811,816

Structured

Asset

Securities

Corp.

Mortgage

Loan

Trust,

Series

2007-MN1A,

Class

A1,

(1-mo.

CME

Term

SOFR

at

0.23%

Floor

+

0.34%),

5.68%,

01/25/37

(b)

(c)

..........

1,141

664,585

Tricon

American

Homes

Trust,

Series

2020-

SFR1,

Class

F,

4.88%,

07/17/38

(b)

......

1,050

1,005,917

WaMu

Asset-Backed

Certificates

Trust,

Series

2007-HE1,

Class

2A3,

(1-mo.

CME

Term

SOFR

at

0.26%

Floor

+

0.26%),

5.60%,

01/25/37

(c)

......................

1,202

549,453

WaMu

Mortgage

Pass-Through

Certificates

Trust,

Series

2007-HE2,

Class

2A3,

(1-mo.

CME

Term

SOFR

at

0.36%

Floor

+

0.36%),

5.70%,

04/25/37

(c)

.................

1,350

496,080

Washington

Mutual

Asset-Backed

CertificatesTrust,

Series

2007-HE2,

Class

2A1,

(1-mo.

CME

Term

SOFR

at

0.10%

Floor

+

0.21%),

5.55%,

02/25/37

(c)

......

2,908

792,919

Total

Asset-Backed

Securities

—

17

.1

%

(Cost:

$

51,223,962

)

...............................

48,843,074

Corporate

Bonds

Financial

Services

—

0.2%

CRSO

Trust,

7.12%,

07/10/28

(b)

.........

427

450,052

Total

Corporate

Bonds

—

0

.2

%

(Cost:

$

427,580

)

.................................

450,052

Non-Agency

Mortgage-Backed

Securities

Collateralized

Mortgage

Obligations

—

18.1%

Alternative

Loan

Trust

Series

2005-54CB,

Class

3A1,

5.13%,

11/25/35

.....................

1,111

597,197

Series

2005-79CB,

Class

A1,

(1-mo.

CME

Term

SOFR

at

0.55%

Floor

and

5.50%

Cap

+

0.66%),

5.50%,

01/25/36

(c)

.....

1,803

915,892

Series

2006-45T1,

Class

2A7,

(1-mo.

CME

Term

SOFR

at

0.34%

Floor

and

7.00%

Cap

+

0.45%),

5.79%,

02/25/37

(c)

.....

1,483

587,983

Series

2006-6CB,

Class

2A10,

6.00%,

05/25/36

.....................

1,973

820,470

Series

2006-9T1,

Class

A4,

5.75%,

05/25/36

1,714

668,767

Series

2007-19,

Class

1A34,

6.00%,

08/25/37

.....................

756

383,441

Banc

of

America

Mortgage

Trust,

Series

2005-I,

Class

2A5,

4.71%,

10/25/35

(c)

.........

72

66,103

Barclays

Mortgage

Trust

(b)

Series

2021-NPL1,

Class

A,

2.00%,

11/25/51

(a)

....................

2,263

2,161,846

Series

2021-NPL1,

Class

B,

4.62%,

11/25/51

(a)

....................

177

163,797

Series

2021-NPL1,

Class

C,

0.00%,

11/25/51

.....................

388

394,429

Security

Par

(000)

Par

(000)

Value

Collateralized

Mortgage

Obligations

(continued)

BCAP

LLC

Trust,

Series

2012-RR3,

Class

3A8,

3.77%,

07/26/37

(b)

(c)

................

USD

1,334

$

1,151,296

Bear

Stearns

ALT-A

Trust,

Series

2007-1,

Class

1A1,

(1-mo.

CME

Term

SOFR

at

0.32%

Floor

and

11.50%

Cap

+

0.43%),

5.77%,

01/25/47

(c)

......................

614

495,027

CFMT

LLC,

Series

2023-HB11,

Class

M2,

4.00%,

02/25/37

(b)

(c)

................

1,250

1,096,592

Chase

Mortgage

Finance

Trust,

Series

2007-

S2,

Class

1A9,

6.00%,

03/25/37

........

1,736

965,600

ChaseFlex

Trust,

Series

2007-1,

Class

2A7,

6.00%,

02/25/37

..................

1,919

709,189

CHL

Mortgage

Pass-Through

Trust

Series

2005-17,

Class

1A6,

5.50%,

09/25/35

23

20,988

Series

2006-21,

Class

A11,

5.75%,

02/25/37

1,175

524,970

Series

2006-OA4,

Class

A1,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

at

0.96%

Floor

+

0.96%),

6.02%,

04/25/46

(c)

.........

1,241

373,093

Series

2007-8,

Class

1A4,

6.00%,

01/25/38

322

144,700

Citigroup

Mortgage

Loan

Trust

(c)

Series

2004-UST1,

Class

A4,

5.70%,

08/25/34

.....................

392

360,624

Series

2015-A,

Class

B4,

4.50%,

06/25/58

(b)

1,162

1,077,299

CitiMortgage

Alternative

Loan

Trust,

Series

2007-A5,

Class

1A6,

6.00%,

05/25/37

....

500

450,749

CSMC

Trust

(b)

Series

2010-6R,

Class

2A6B,

6.25%,

07/26/37

.....................

610

615,923

Series

2022-ATH2,

Class

A1,

4.55%,

05/25/67

(c)

....................

1,042

1,022,879

GSMPS

Mortgage

Loan

Trust,

Series

2005-

RP2,

Class

1AF,

(1-mo.

CME

Term

SOFR

at

0.35%

Floor

+

0.46%),

5.80%,

03/25/35

(b)

(c)

812

734,838

GSR

Mortgage

Loan

Trust,

Series

2006-9F,

Class

3A1,

6.25%,

10/25/36

..........

561

501,670

Homeward

Opportunities

Fund

I

Trust

(b)(c)

Series

2020-2,

Class

B1,

5.45%,

05/25/65

.

1,985

1,917,729

Series

2020-2,

Class

M1,

3.90%,

05/25/65

.

2,625

2,446,885

Impac

Secured

Assets

Trust,

Series

2006-1,

Class

1A2B,

(1-mo.

CME

Term

SOFR

at

0.40%

Floor

and

11.50%

Cap

+

0.51%),

5.85%,

05/25/36

(c)

.................

928

714,530

IndyMac

IMSC

Mortgage

Loan

Trust,

Series

2007-F2,

Class

1A4,

6.00%,

07/25/37

....

742

530,111

IndyMac

INDX

Mortgage

Loan

Trust,

Series

2006-AR15,

Class

A1,

(1-mo.

CME

Term

SOFR

at

0.24%

Floor

+

0.35%),

5.69%,

07/25/36

(c)

......................

563

544,529

Lehman

XS

Trust,

Series

2007-16N,

Class

AF2,

(1-mo.

CME

Term

SOFR

at

1.90%

Floor

+

2.01%),

7.35%,

09/25/47

(c)

...........

918

1,184,522

MCM

Trust

(e)

Series

2021-VFN1,  3.00%,

08/25/28

(b)

...

534

513,257

Series

2021-VFN1,  0.00%,

09/25/31

(f)

...

405

266,073

New

Residential

Mortgage

Loan

Trust,

Series

2020-RPL1,

Class

B3,

3.88%,

11/25/59

(b)

(c)

.

2,500

1,764,007

PRPM

LLC,

Series

2022-1,

Class

A1,

3.72%,

02/25/27

(a)

(b)

.....................

1,505

1,455,025

RALI

Trust

(c)

Series

2005-QA4,

Class

A11,

4.52%,

04/25/35

.....................

2,116

896,761

Series

2007-QS1,

Class

1A5,

(1-mo.

CME

Term

SOFR

at

0.55%

Floor

and

6.00%

Cap

+

0.66%),

6.00%,

01/25/37

......

955

671,834

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

4

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Collateralized

Mortgage

Obligations

(continued)

Reperforming

Loan

REMIC

Trust,

Series

2005-R3,

Class

AF,

(1-mo.

CME

Term

SOFR

at

0.40%

Floor

and

9.50%

Cap

+

0.51%),

5.85%,

09/25/35

(b)

(c)

................

USD

137

$

114,721

Residential

Asset

Securitization

Trust

(c)

Series

2006-A7CB,

Class

2A2,

(1-mo.

CME

Term

SOFR

at

0.55%

Floor

and

6.50%

Cap

+

0.66%),

6.00%,

07/25/36

......

2,605

508,726

Series

2006-A7CB,

Class

2A5,

(1-mo.

CME

Term

SOFR

at

0.25%

Floor

and

7.00%

Cap

+

0.36%),

5.70%,

07/25/36

......

570

104,793

Series

2006-A7CB,

Class

2A6,

(1-mo.

CME

Term

SOFR

at

54.00%

Cap

+

53.08%),

10.40%,

07/25/36

...............

458

436,767

RFMSI

Trust

(c)

Series

2005-SA3,

Class

1A,

4.11%,

08/25/35

1,599

691,335

Series

2006-SA2,

Class

2A1,

5.36%,

08/25/36

.....................

99

68,788

RMF

Buyout

Issuance

Trust,

Series

2021-HB1,

Class

M6,

6.00%,

11/25/31

(b)

(c)

(e)

........

1,708

1,125,399

Seasoned

Loans

Structured

Transaction

Trust

(b)

(c)

Series

2020-2,

Class

M1,

4.75%,

09/25/60

.

2,748

2,631,891

Series

2020-3,

Class

M1,

4.75%,

04/26/60

.

2,829

2,743,901

Spruce

Hill

Mortgage

Loan

Trust

(b)

Series

2020-SH2,

Class

B1,

5.00%,

06/25/55

(c)

....................

2,764

2,618,684

Series

2022-SH1,

Class

A1A,

4.10%,

07/25/57

(a)

....................

1,237

1,183,641

TVC

Mortgage

Trust,

Series

2023-RTL1,

Class

A1,

8.25%,

11/25/27

(a)

(b)

.............

395

397,424

Verus

Securitization

Trust

(b)(c)

Series

2020-INV1,

Class

B1,

5.75%,

03/25/60

.....................

1,100

1,031,603

Series

2023-INV1,

Class

M1,

7.59%,

02/25/68

.....................

1,200

1,217,972

WaMu

Mortgage

Pass-Through

Certificates

Trust,

Series

2007-OA5,

Class

2A,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

at

1.25%

Floor

+

0.80%),

5.86%,

06/25/47

(c)

......................

1,695

1,338,884

Washington

Mutual

Mortgage

Pass-Through

Certificates

WMALT

Trust

Series

2005-11,

Class

A7,

5.75%,

01/25/36

1,142

961,427

Series

2005-9,

Class

5A1,

5.50%,

11/25/35

1,073

821,478

Series

2006-2,

Class

2CB,

6.50%,

03/25/36

717

459,761

Series

2006-2,

Class

3CB,

6.00%,

03/25/36

1,056

795,052

Series

2006-6,

Class

3CB1,

7.00%,

08/25/36

.....................

2,805

1,105,266

Series

2006-AR8,

Class

2A,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

at

0.85%

Floor

+

0.85%),

5.91%,

10/25/46

(c)

.........

105

82,594

Series

2007-5,

Class

A3,

7.00%,

06/25/37

.

204

155,792

Western

Mortgage

Reference

Notes

(b)(c)

Series

2021-CL2,

Class

M1,

(SOFR

30

day

Average

+

3.15%),

8.49%,

07/25/59

...

467

493,290

Series

2021-CL2,

Class

M2,

(SOFR

30

day

Average

+

3.70%),

9.04%,

07/25/59

...

668

679,826

51,679,640

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

—

23.8%

1211

Avenue

of

the

Americas

Trust,

Series

2015-1211,

Class

A1A2,

3.90%,

08/10/35

(b)

USD

370

$

357,866

280

Park

Avenue

Mortgage

Trust,

Series

2017-

280P,

Class

E,

(1-mo.

CME

Term

SOFR

at

1.48%

Floor

+

2.42%),

7.76%,

09/15/34

(b)

(c)

137

125,218

Alen

Mortgage

Trust,

Series

2021-ACEN,

Class

D,

(1-mo.

CME

Term

SOFR

at

3.10%

Floor

+

3.21%),

8.55%,

04/15/34

(b)

(c)

..........

276

172,145

Arbor

Multifamily

Mortgage

Securities

Trust,

Series

2020-MF1,

Class

E,

1.75%,

05/15/53

(b)

......................

750

480,498

Ashford

Hospitality

Trust

(b)(c)

Series

2018-ASHF,

Class

D,

(1-mo.

CME

Term

SOFR

at

2.10%

Floor

+

2.27%),

7.61%,

04/15/35

................

280

270,006

Series

2018-ASHF,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.23%

Floor

+

3.27%),

8.61%,

04/15/35

................

229

222,245

BAMLL

Commercial

Mortgage

Securities

Trust

(b)

(c)

Series

2018-DSNY,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.10%

Floor

+

1.15%),

6.48%,

09/15/34

................

529

528,756

Series

2018-DSNY,

Class

D,

(1-mo.

CME

Term

SOFR

at

1.95%

Floor

+

2.00%),

7.33%,

09/15/34

................

160

158,130

BANK

Series

2021-BN35,

Class

A5,

2.29%,

06/15/64

.....................

730

614,307

Series

2021-BN38,

Class

A5,

2.52%,

12/15/64

.....................

1,700

1,433,176

Bayview

Commercial

Asset

Trust

(b)(c)

Series

2006-3A,

Class

A2,

(1-mo.

CME

Term

SOFR

+

0.56%),

5.90%,

10/25/36

....

671

630,874

Series

2006-4A,

Class

A1,

(1-mo.

CME

Term

SOFR

+

0.46%),

5.80%,

12/25/36

....

567

528,076

BBCMS

Mortgage

Trust

Series

2018-TALL,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.87%

Floor

+

0.92%),

6.25%,

03/15/37

(b)

(c)

..............

296

282,005

Series

2018-TALL,

Class

B,

(1-mo.

CME

Term

SOFR

at

1.12%

Floor

+

1.17%),

6.50%,

03/15/37

(b)

(c)

..............

150

137,250

Series

2020-C7,

Class

A5,

2.04%,

04/15/53

1,950

1,655,173

Series

2022-C18,

Class

ASB,

5.95%,

12/15/55

(c)

....................

650

692,262

Beast

Mortgage

Trust,

Series

2021-SSCP,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.75%

Floor

+

0.86%),

6.20%,

04/15/36

(b)

(c)

.....

691

683,010

BFLD

Trust,

Series

2020-EYP,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.70%

Floor

+

3.81%),

9.15%,

10/15/35

(b)

(c)

................

120

12,612

BHMS,

Series

2018-ATLS,

Class

C,

(1-mo.

CME

Term

SOFR

at

2.15%

Floor

+

2.20%),

7.53%,

07/15/35

(b)

(c)

................

269

262,356

BPR

Trust

(b)(c)

Series

2021-TY,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.05%

Floor

+

1.16%),

6.50%,

09/15/38

.....................

1,000

984,408

Series

2021-TY,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.60%

Floor

+

3.71%),

9.05%,

09/15/38

.....................

750

737,578

Series

2022-SSP,

Class

A,

(1-mo.

CME

Term

SOFR

at

3.00%

Floor

+

3.00%),

8.33%,

05/15/39

.....................

370

371,972

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

5

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

BX

Commercial

Mortgage

Trust

(b)

Series

2019-XL,

Class

D,

(1-mo.

CME

Term

SOFR

at

1.45%

Floor

+

1.56%),

6.90%,

10/15/36

(c)

....................

USD

1,190

$

1,185,451

Series

2020-VIV3,

Class

B,

3.66%,

03/09/44

(c)

....................

683

607,531

Series

2020-VIV4,

Class

A,

2.84%,

03/09/44

1,370

1,197,957

Series

2021-SOAR,

Class

G,

(1-mo.

CME

Term

SOFR

at

2.80%

Floor

+

2.91%),

8.25%,

06/15/38

(c)

...............

139

135,378

Series

2021-VINO,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.77%

Floor

+

0.77%),

6.10%,

05/15/38

(c)

...............

620

613,388

Series

2021-VINO,

Class

F,

(1-mo.

CME

Term

SOFR

at

2.92%

Floor

+

2.92%),

8.25%,

05/15/38

(c)

...............

132

128,633

Series

2021-XL2,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.69%

Floor

+

0.80%),

6.14%,

10/15/38

(c)

....................

2,692

2,656,913

Series

2022-CSMO,

Class

C,

(1-mo.

CME

Term

SOFR

at

3.89%

Floor

+

3.89%),

9.22%,

06/15/27

(c)

...............

260

260,487

Series

2022-LP2,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.01%

Floor

+

1.01%),

6.35%,

02/15/39

(c)

....................

1,369

1,357,466

Series

2022-LP2,

Class

B,

(1-mo.

CME

Term

SOFR

at

1.31%

Floor

+

1.31%),

6.65%,

02/15/39

(c)

....................

1,256

1,236,774

Series

2024-XL4,

Class

D,

(1-mo.

CME

Term

SOFR

at

3.14%

Floor

+

3.14%),

8.54%,

02/15/39

(c)

....................

256

255,360

BX

Trust

(b)

Series

2019-OC11,

Class

A,

3.20%,

12/09/41

.....................

826

744,049

Series

2019-OC11,

Class

E,

4.08%,

12/09/41

(c)

....................

71

61,075

Series

2021-ARIA,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.90%

Floor

+

1.01%),

6.35%,

10/15/36

(c)

...............

300

295,875

Series

2021-ARIA,

Class

G,

(1-mo.

CME

Term

SOFR

at

3.14%

Floor

+

3.26%),

8.59%,

10/15/36

(c)

...............

128

121,854

Series

2021-LBA,

Class

AJV,

(1-mo.

CME

Term

SOFR

at

0.80%

Floor

+

0.91%),

6.25%,

02/15/36

(c)

...............

705

699,052

Series

2021-MFM1,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.70%

Floor

+

0.81%),

6.15%,

01/15/34

(c)

...............

383

380,018

Series

2021-VIEW,

Class

D,

(1-mo.

CME

Term

SOFR

at

2.90%

Floor

+

3.01%),

8.35%,

06/15/36

(c)

...............

275

261,463

Series

2022-GPA,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.17%

Floor

+

2.17%),

7.50%,

08/15/39

(c)

...............

169

169,009

Series

2022-GPA,

Class

B,

(1-mo.

CME

Term

SOFR

at

2.66%

Floor

+

2.66%),

8.00%,

08/15/41

(c)

...............

695

695,919

Series

2022-GPA,

Class

D,

(1-mo.

CME

Term

SOFR

at

4.06%

Floor

+

4.06%),

9.39%,

08/15/43

(c)

...............

298

298,251

Series

2022-IND,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.49%

Floor

+

1.49%),

6.82%,

04/15/37

(c)

....................

108

108,022

Series

2022-LBA6,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.00%

Floor

+

1.00%),

6.33%,

01/15/39

(c)

...............

700

694,312

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Series

2022-VAMF,

Class

F,

(1-mo.

CME

Term

SOFR

at

3.30%

Floor

+

3.30%),

8.63%,

01/15/39

(c)

...............

USD

450

$

418,617

Series

2024-BIO,

Class

A,

(1-mo.

CME

Term

SOFR

+

1.64%),

6.94%,

02/15/41

(c)

...

410

409,872

BXP

Trust,

Series

2021-601L,

Class

D,

2.87%,

01/15/44

(b)

(c)

.....................

540

345,391

CFCRE

Commercial

Mortgage

Trust,

Series

2016-C7,

Class

A3,

3.84%,

12/10/54

.....

600

572,807

CFK

Trust,

Series

2020-MF2,

Class

B,

2.79%,

03/15/39

(b)

......................

336

285,603

COAST

Commercial

Mortgage

Trust,

Series

2023-2HTL,

Class

B,

(1-mo.

CME

Term

SOFR

at

3.34%

Floor

+

3.34%),

8.67%,

08/15/36

(b)

(c)

.....................

250

252,450

Cold

Storage

Trust

(b)(c)

Series

2020-ICE5,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.90%

Floor

+

1.01%),

6.35%,

11/15/37

................

688

685,946

Series

2020-ICE5,

Class

F,

(1-mo.

CME

Term

SOFR

at

3.49%

Floor

+

3.61%),

8.95%,

11/15/37

................

703

698,076

Commercial

Mortgage

Trust

Series

2014-UBS2,

Class

A5,

3.96%,

03/10/47

.....................

14

13,683

Series

2015-CR25,

Class

A3,

3.51%,

08/10/48

.....................

492

479,913

Series

2015-CR25,

Class

C,

4.67%,

08/10/48

(c)

....................

255

243,222

Series

2015-LC19,

Class

B,

3.83%,

02/10/48

(c)

....................

806

765,921

Series

2017-PANW,

Class

A,

3.24%,

10/10/29

(b)

....................

1,580

1,445,700

Credit

Suisse

Mortgage

Capital

Certificates

(b)(c)

Series

2019-ICE4,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.98%

Floor

+

1.03%),

6.36%,

05/15/36

................

549

548,292

Series

2019-ICE4,

Class

E,

(1-mo.

CME

Term

SOFR

at

2.15%

Floor

+

2.20%),

7.53%,

05/15/36

................

279

278,248

CSAIL

Commercial

Mortgage

Trust,

Series

2019-C16,

Class

C,

4.24%,

06/15/52

(c)

...

251

214,839

CSMC

Trust

(b)

Series

2020-FACT,

Class

F,

(1-mo.

CME

Term

SOFR

at

6.16%

Floor

+

6.52%),

11.86%,

10/15/37

(c)

..............

600

520,933

Series

2020-NET,

Class

C,

3.53%,

08/15/37

100

91,962

Series

2021-980M,

Class

E,

3.65%,

07/15/31

(c)

....................

365

322,414

Series

2021-BHAR,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.50%

Floor

+

3.61%),

8.95%,

11/15/38

(c)

...............

300

293,353

Series

2022-NWPT,

Class

A,

(1-mo.

CME

Term

SOFR

at

3.14%

Floor

+

3.14%),

8.48%,

09/09/24

(c)

...............

380

382,137

DBGS

Mortgage

Trust,

Series

2018-BIOD,

Class

F,

(1-mo.

CME

Term

SOFR

at

2.00%

Floor

+

2.30%),

7.63%,

05/15/35

(b)

(c)

.....

210

204,943

Extended

Stay

America

Trust

(b)(c)

Series

2021-ESH,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.08%

Floor

+

1.19%),

6.53%,

07/15/38

................

354

352,388

Series

2021-ESH,

Class

F,

(1-mo.

CME

Term

SOFR

at

3.70%

Floor

+

3.81%),

9.15%,

07/15/38

................

741

737,395

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

6

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Great

Wolf

Trust,

Series

2019-WOLF,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.12%

Floor

+

1.35%),

6.68%,

12/15/36

(b)

(c)

..........

USD

608

$

607,813

GS

Mortgage

Securities

Corp.

II

(b)

Series

2005-ROCK,

Class

A,

5.37%,

05/03/32

.....................

335

328,327

Series

2023-SHIP,

Class

E,

7.68%,

09/10/38

(c)

....................

700

687,772

GS

Mortgage

Securities

Corp.

Trust

(b)(c)

Series

2021-IP,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.55%

Floor

+

3.66%),

9.00%,

10/15/36

.....................

300

294,773

Series

2021-STAR,

Class

B,

(1-mo.

CME

Term

SOFR

at

1.40%

Floor

+

1.51%),

6.85%,

12/15/36

................

870

856,233

Series

2022-AGSS,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.79%

Floor

+

2.69%),

8.03%,

11/15/27

................

374

374,949

Series

2023-FUN,

Class

B,

(1-mo.

CME

Term

SOFR

at

2.79%

Floor

+

2.79%),

8.12%,

03/15/28

................

520

520,162

Hawaii

Hotel

Trust,

Series

2019-MAUI,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.15%

Floor

+

1.20%),

6.53%,

05/15/38

(b)

(c)

..........

250

249,063

Hilton

USA

Trust,

Series

2016-HHV,

Class

C,

4.33%,

11/05/38

(b)

(c)

................

519

494,178

HONO

Mortgage

Trust

(b)(c)

Series

2021-LULU,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.15%

Floor

+

1.26%),

6.60%,

10/15/36

................

772

743,644

Series

2021-LULU,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.35%

Floor

+

3.46%),

8.80%,

10/15/36

................

590

550,256

Series

2021-LULU,

Class

F,

(1-mo.

CME

Term

SOFR

at

4.40%

Floor

+

4.51%),

9.85%,

10/15/36

................

410

376,137

Hudson

Yards

Mortgage

Trust,

Series

2019-

30HY,

Class

D,

3.56%,

07/10/39

(b)

(c)

.....

208

175,063

IMT

Trust,

Series

2017-APTS,

Class

BFX,

3.61%,

06/15/34

(b)

(c)

................

1,250

1,230,298

JPMorgan

Chase

Commercial

Mortgage

Securities

Trust

(b)(c)

Series

2016-NINE,

Class

A,

2.95%,

09/06/38

640

599,396

Series

2016-NINE,

Class

B,

(1-mo.

LIBOR

USD

+

0.00%),

2.95%,

09/06/38

.....

654

593,472

Series

2021-MHC,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.80%

Floor

+

0.91%),

6.25%,

04/15/38

................

576

574,226

Series

2022-CGSS,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.97%

Floor

+

2.87%),

8.21%,

12/15/36

................

532

533,467

Series

2022-NXSS,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.18%

Floor

+

2.18%),

7.51%,

09/15/39

................

539

540,344

Series

2022-OPO,

Class

D,

3.56%,

01/05/39

350

224,875

Lehman

Brothers

Small

Balance

Commercial

Mortgage

Trust,

Series

2007-2A,

Class

M1,

(1-mo.

CME

Term

SOFR

at

0.40%

Floor

+

0.51%),

5.85%,

06/25/37

(b)

(c)

..........

669

661,333

Life

Mortgage

Trust,

Series

2021-BMR,

Class

F,

(1-mo.

CME

Term

SOFR

at

2.35%

Floor

+

2.46%),

7.80%,

03/15/38

(b)

(c)

..........

164

158,572

LUX

Trust,

Series

2023-LION,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.69%

Floor

+

2.69%),

8.02%,

08/15/40

(b)

(c)

................

128

129,191

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Med

Trust

(b)(c)

Series

2021-MDLN,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.95%

Floor

+

1.06%),

6.40%,

11/15/38

................

USD

554

$

548,796

Series

2021-MDLN,

Class

E,

(1-mo.

CME

Term

SOFR

at

3.15%

Floor

+

3.26%),

8.60%,

11/15/38

................

146

143,359

Series

2021-MDLN,

Class

F,

(1-mo.

CME

Term

SOFR

at

4.00%

Floor

+

4.11%),

9.45%,

11/15/38

................

141

138,849

Series

2021-MDLN,

Class

G,

(1-mo.

CME

Term

SOFR

at

5.25%

Floor

+

5.36%),

10.70%,

11/15/38

...............

244

237,734

MF1

Multifamily

Housing

Mortgage

Loan

Trust

(b)

(c)

Series

2021-W10,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.07%

Floor

+

1.07%),

6.40%,

12/15/34

................

470

459,321

Series

2021-W10,

Class

G,

(1-mo.

CME

Term

SOFR

at

4.25%

Floor

+

4.22%),

9.55%,

12/15/34

................

300

279,990

MFT

Trust,

Series

2020-ABC,

Class

C,

3.59%,

02/10/42

(b)

(c)

.....................

192

109,485

MHC

Commercial

Mortgage

Trust,

Series

2021-

MHC,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.80%

Floor

+

0.92%),

6.25%,

04/15/38

(b)

(c)

320

317,714

MIRA

Trust,

Series

2023-MILE,

Class

A,

6.75%,

06/10/38

(b)

......................

128

133,537

Morgan

Stanley

Capital

I

Trust

Series

2014-150E,

Class

A,

3.91%,

09/09/32

(b)

....................

595

507,491

Series

2017-HR2,

Class

D,

2.73%,

12/15/50

(b)

....................

555

453,007

Series

2018-H4,

Class

A4,

4.31%,

12/15/51

1,824

1,769,239

Series

2018-SUN,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.90%

Floor

+

1.20%),

6.54%,

07/15/35

(b)

(c)

..............

595

591,998

Natixis

Commercial

Mortgage

Securities

Trust,

Series

2018-FL1,

Class

A,

(US

Prime

Rate

+

1.00%),

8.50%,

06/15/35

(b)

(c)

..........

28

25,420

One

Bryant

Park

Trust,

Series

2019-OBP,

Class

A,

2.52%,

09/15/54

(b)

...............

1,072

924,937

OPEN

Trust,

Series

2023-AIR,

Class

A,

(1-mo.

CME

Term

SOFR

at

3.09%

Floor

+

3.09%),

8.42%,

10/15/28

(b)

(c)

................

330

331,514

PKHL

Commercial

Mortgage

Trust,

Series

2021-MF,

Class

NR,

(1-mo.

CME

Term

SOFR

at

6.00%

Floor

+

6.11%),

11.45%,

07/15/38

(b)

(c)

.....................

300

48,658

SMRT,

Series

2022-MINI,

Class

A,

(1-mo.

CME

Term

SOFR

at

1.00%

Floor

+

1.00%),

6.33%,

01/15/39

(b)

(c)

................

566

559,748

SREIT

Trust

(b)(c)

Series

2021-MFP,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.73%

Floor

+

0.85%),

6.18%,

11/15/38

................

574

568,377

Series

2021-MFP,

Class

F,

(1-mo.

CME

Term

SOFR

at

2.63%

Floor

+

2.74%),

8.07%,

11/15/38

.....................

718

687,767

Series

2021-MFP2,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.82%

Floor

+

0.94%),

6.27%,

11/15/36

................

1,255

1,244,803

STWD

Trust,

Series

2021-FLWR,

Class

A,

(1-mo.

CME

Term

SOFR

at

0.58%

Floor

+

0.69%),

6.02%,

07/15/36

(b)

(c)

..........

1,243

1,226,297

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

7

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Taubman

Centers

Commercial

Mortgage

Trust,

Series

2022-DPM,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.19%

Floor

+

2.19%),

7.52%,

05/15/37

(b)

(c)

................

USD

500

$

498,745

Velocity

Commercial

Capital

Loan

Trust

(b)(c)

Series

2019-3,

Class

M4,

3.68%,

10/25/49

.

1,205

981,725

Series

2019-3,

Class

M6,

6.03%,

10/25/49

.

1,279

896,134

Series

2020-1,

Class

M4,

3.54%,

02/25/50

.

626

503,805

Series

2021-4,

Class

M5,

5.68%,

12/26/51

.

1,970

1,461,549

Wells

Fargo

Commercial

Mortgage

Trust

Series

2015-C26,

Class

AS,

3.58%,

02/15/48

.....................

408

393,874

Series

2015-C30,

Class

B,

4.40%,

09/15/58

(c)

....................

500

480,150

Series

2016-C32,

Class

B,

4.89%,

01/15/59

(c)

....................

500

476,168

Series

2018-1745,

Class

A,

3.87%,

06/15/36

(b)

(c)

...................

1,990

1,730,377

Series

2018-AUS,

Class

A,

4.19%,

08/17/36

(b)

(c)

...................

620

581,204

Series

2020-SDAL,

Class

B,

(1-mo.

CME

Term

SOFR

at

1.34%

Floor

+

1.45%),

6.79%,

02/15/37

(b)

(c)

..............

405

400,898

WMRK

Commercial

Mortgage

Trust,

Series

2022-WMRK,

Class

A,

(1-mo.

CME

Term

SOFR

at

2.79%

Floor

+

2.79%),

8.12%,

11/15/27

(b)

(c)

.....................

660

662,063

67,946,542

Interest

Only

Collateralized

Mortgage

Obligations

—

0.2%

(c)

Alternative

Loan

Trust,

Series

2006-45T1,

Class

2A8,

(1-mo.

CME

Term

SOFR

at

6.60%

Cap

+

6.49%),

1.15%,

02/25/37

...........

742

120,621

GSR

Mortgage

Loan

Trust,

Series

2007-3F,

Class

4A2,

(1-mo.

CME

Term

SOFR

at

6.70%

Cap

+

6.59%),

1.25%,

05/25/37

...

3,858

474,326

594,947

Interest

Only

Commercial

Mortgage-Backed

Securities

—

1.2%

(c)

BANK,

Series

2017-BNK9,

Class

XA,

0.90%,

11/15/54

........................

3,396

73,722

BBCMS

Mortgage

Trust

Series

2020-C7,

Class

XA,

1.73%,

04/15/53

2,983

183,535

Series

2020-C7,

Class

XB,

1.10%,

04/15/53

1,000

53,558

Series

2023-C20,

Class

XA,

1.07%,

07/15/56

.....................

11,999

652,397

Benchmark

Mortgage

Trust

Series

2020-B17,

Class

XB,

(1-mo.

LIBOR

USD

+

0.00%),

0.65%,

03/15/53

.....

15,395

365,665

Series

2023-V3,

Class

XA,

1.05%,

07/15/56

19,996

635,685

Citigroup

Commercial

Mortgage

Trust,

Series

2020-420K,

Class

X,

0.91%,

11/10/42

(b)

...

3,975

180,637

CSAIL

Commercial

Mortgage

Trust

Series

2018-C14,

Class

XA,

0.70%,

11/15/51

.....................

1,044

20,732

Series

2019-C16,

Class

XA,

1.70%,

06/15/52

.....................

3,880

238,100

MIRA

Trust,

Series

2023-MILE,

Class

X,

0.25%,

06/10/38

(b)

......................

28,000

108,195

ORL

Trust,

Series

2023-GLKS,

Class

XCP,

0.48%,

10/19/36

(b)

.................

115,920

387,973

UBS

Commercial

Mortgage

Trust,

Series

2019-

C17,

Class

XA,

1.60%,

10/15/52

.......

3,178

192,379

Security

Par

(000)

Par

(000)

Value

Interest

Only

Commercial

Mortgage-Backed

Securities

(continued)

Wells

Fargo

Commercial

Mortgage

Trust,

Series

2017-C41,

Class

XA,

1.30%,

11/15/50

....

USD

3,590

$

125,653

3,218,231

Total

Non-Agency

Mortgage-Backed

Securities

—

43

.3

%

(Cost:

$

129,964,737

)

..............................

123,439,360

U.S.

Government

Sponsored

Agency

Securities

Collateralized

Mortgage

Obligations

—

0.4%

Federal

Home

Loan

Mortgage

Corp.

,

Series

4161

,

Class

BW

,

2.50

%

,

02/15/43

......

200

171,649

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

,

Series

2411

,

Class

FJ

,

(SOFR

30

day

Average

at

0.35%

Floor

and

9.00%

Cap

+

0.46%),

5.81

%

,

12/15/29

(c)

.......

2

1,760

Federal

National

Mortgage

Association

Series

2010-134

,

Class

KZ

,

4.50

%

,

12/25/40

107

96,387

Series

2010-141

,

Class

LZ

,

4.50

%

,

12/25/40

219

211,920

Series

2011-131

,

Class

LZ

,

4.50

%

,

12/25/41

151

139,668

Federal

National

Mortgage

Association

Variable

Rate

Notes

,

Series

2018-32

,

Class

PS

,

(SOFR

30

day

Average

at

7.23%

Cap

+

7.10%),

0.86

%

,

05/25/48

(c)

...........

158

136,535

Government

National

Mortgage

Association

,

Series

2019-29

,

Class

HY

,

3.50

%

,

03/20/49

100

81,725

Government

National

Mortgage

Association

Variable

Rate

Notes

,

Series

2014-107

,

Class

WX

,

6.65

%

,

07/20/39

(c)

..............

147

152,448

992,092

Commercial

Mortgage-Backed

Securities

—

0.1%

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

,

Series

2018-W5FX

,

Class

CFX

,

(1-mo.

LIBOR

USD

+

0.00%),

3.79

%

,

04/25/28

(b)

(c)

................

288

248,289

Government

National

Mortgage

Association

,

Series

2019-53

,

Class

V

,

2.75

%

,

08/16/31

.

164

150,431

398,720

Interest

Only

Collateralized

Mortgage

Obligations

—

5.2%

Federal

Home

Loan

Mortgage

Corp.

Series

4062

,

Class

GI

,

4.00

%

,

02/15/41

..

78

3,140

Series

5159

,

Class

KI

,

3.00

%

,

11/25/51

...

553

69,967

Series

5159

,

Class

PI

,

3.00

%

,

11/25/51

...

859

123,753

Series

5176

,

Class

QI

,

3.00

%

,

12/25/51

..

557

82,608

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

(c)

Series

4119

,

Class

SC

,

(SOFR

30

day

Average

at

6.15%

Cap

+

6.04%),

0.69

%

,

10/15/42

................

625

71,806

Series

4901

,

Class

CS

,

(SOFR

30

day

Average

at

6.10%

Cap

+

5.99%),

0.64

%

,

07/25/49

................

447

49,150

Series

4941

,

Class

SH

,

(SOFR

30

day

Average

at

5.95%

Cap

+

5.84%),

0.49

%

,

12/25/49

................

418

41,745

Federal

National

Mortgage

Association

Series

2013-10

,

Class

PI

,

3.00

%

,

02/25/43

456

53,013

Series

2014-68

,

Class

YI

,

4.50

%

,

11/25/44

.

201

40,298

Series

2017-68

,

Class

IE

,

4.50

%

,

09/25/47

582

102,415

Series

2021-23

,

Class

CI

,

3.50

%

,

07/25/46

592

97,753

Series

2021-41

,

3.50

%

,

07/25/51

.......

708

122,370

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

8

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Par

(000)

Value

Interest

Only

Collateralized

Mortgage

Obligations

(continued)

Federal

National

Mortgage

Association

Variable

Rate

Notes

(c)

Series

2016-60

,

Class

SD

,

(SOFR

30

day

Average

at

6.10%

Cap

+

5.99%),

0.64

%

,

09/25/46

................

USD

868

$

71,298

Series

2016-78

,

Class

CS

,

(SOFR

30

day

Average

at

6.10%

Cap

+

5.99%),

0.64

%

,

05/25/39

................

1,107

88,909

Series

2017-70

,

Class

SA

,

(SOFR

30

day

Average

at

6.15%

Cap

+

6.04%),

0.69

%

,

09/25/47

................

567

71,149

Government

National

Mortgage

Association

Series

2021-58

,

Class

IY

,

3.00

%

,

02/20/51

.

17,999

2,739,469

Series

2021-64

,

Class

IH

,

3.00

%

,

02/20/51

19,698

3,047,490

Series

2021-97

,

Class

LI

,

3.00

%

,

08/20/50

.

21,580

3,289,042

Series

2021-104

,

Class

IH

,

3.00

%

,

06/20/51

1,020

153,099

Series

2022-88

,

Class

IA

,

3.00

%

,

08/20/50

28,732

4,501,796

Government

National

Mortgage

Association

Variable

Rate

Notes

,

Series

2017-101

,

Class

SL

,

(1-mo.

CME

Term

SOFR

at

6.20%

Cap

+

6.09%),

0.75

%

,

07/20/47

(c)

...........

380

44,892

14,865,162

Interest

Only

Commercial

Mortgage-Backed

Securities

—

0.4%

(c)

Federal

Home

Loan

Mortgage

Corp.

Multifamily

Structured

Pass-Through

Certificates

Variable

Rate

Notes

Series

K110

,

Class

X1

,

1.81

%

,

04/25/30

..

5,309

427,391

Series

KPLB2

,

Class

X

,

0.44

%

,

06/25/33

..

16,982

381,899

Government

National

Mortgage

Association

Variable

Rate

Notes

Series

2016-151

,

0.85

%

,

06/16/58

......

7,694

296,326

Series

2020-43

,

1.26

%

,

11/16/61

.......

2,115

151,102

1,256,718

Mortgage-Backed

Securities

—

55.3%

Federal

Home

Loan

Mortgage

Corp.

2.50

%

,

03/01/30

-

04/01/31

...........

491

466,190

3.00

%

,

09/01/27

-

12/01/46

...........

306

285,514

3.50

%

,

12/01/41

-

01/01/48

...........

1,075

1,007,937

4.00

%

,

08/01/40

-

12/01/45

...........

319

307,152

4.50

%

,

07/01/26

-

09/01/48

...........

438

435,486

5.00

%

,

05/01/35

-

02/01/42

...........

576

581,929

5.50

%

,

02/01/35

-

06/01/41

...........

310

319,436

6.00

%

,

08/01/28

-

11/01/39

...........

11

11,550

Federal

National

Mortgage

Association

3.50

%

,

11/01/46

..................

315

295,863

4.00

%

,

01/01/41

..................

26

24,865

6.00

%

,

07/01/39

..................

236

241,617

Federal

National

Mortgage

Association

Variable

Rate

Notes

(c)

3.06

%

,

09/01/27

..................

160

153,215

3.22

%

,

03/01/27

..................

487

470,321

Government

National

Mortgage

Association

3.00

%

,

02/15/45

-

01/20/51

...........

670

603,660

3.50

%

,

01/15/42

-

10/20/46

...........

749

703,528

4.00

%

,

04/20/39

-

06/20/50

...........

2,493

2,387,747

4.50

%

,

09/20/39

-

04/20/47

...........

1,430

1,423,154

5.00

%

,

12/15/34

-

07/20/44

...........

993

1,008,534

5.50

%

,

07/15/38

-

12/20/41

...........

329

339,969

6.50

%

,

10/15/38

-

02/20/41

...........

95

98,667

Uniform

Mortgage-Backed

Securities

1.50

%

,

02/25/39

-

02/25/54

(g)

..........

8,437

6,902,585

2.00

%

,

10/01/31

-

12/01/31

...........

255

237,458

2.00

%

,

02/25/39

-

02/25/54

(g)

..........

24,410

19,944,824

2.50

%

,

04/01/30

-

03/01/32

...........

798

756,321

Security

Par

(000)

Par

(000)

Value

Mortgage-Backed

Securities

(continued)

2.50

%

,

02/25/39

-

02/25/54

(g)

..........

USD

24,981

$

21,129,621

3.00

%

,

04/01/28

-

08/01/50

...........

2,050

1,925,626

3.00

%

,

02/25/54

(g)

.................

11,706

10,244,579

3.50

%

,

11/01/27

-

06/01/52

...........

7,093

6,506,262

3.50

%

,

02/25/54

(g)

.................

7,557

6,877,340

4.00

%

,

08/01/31

-

05/01/52

...........

5,167

4,931,718

4.00

%

,

02/25/54

(g)

.................

5,178

4,873,948

4.50

%

,

07/01/24

-

10/01/52

...........

10,139

9,898,015

4.50

%

,

02/25/54

(g)

.................

16,073

15,539,513

5.00

%

,

06/01/26

-

10/01/52

...........

7,064

7,062,301

5.00

%

,

02/25/54

(g)

.................

14,351

14,163,111

5.50

%

,

05/01/34

-

03/01/53

...........

11,923

12,086,308

6.00

%

,

12/01/32

-

09/01/40

...........

310

322,461

6.00

%

,

02/25/54

(g)

.................

3,075

3,117,101

6.50

%

,

09/01/36

-

05/01/40

...........

82

86,270

157,771,696

Principal

Only

Collateralized

Mortgage

Obligations

—

0.6%

Government

National

Mortgage

Association

,

Series

2023-130

,

Class

OD

,

0.00

%

,

09/20/53

..................

2,184

1,772,400

Total

U.S.

Government

Sponsored

Agency

Securities

—

62

.0

%

(Cost:

$

178,538,620

)

..............................

177,056,788

Total

Long-Term

Investments

—

122.6%

(Cost:

$

360,154,899

)

..............................

349,789,274

Shares

Shares

Short-Term

Securities

Money

Market

Funds

—

0.7%

Dreyfus

Treasury

Prime

Cash

Management

Institutional

Shares

,

5.24

%

(h)

..........

1,984,450

1,984,450

Total

Money

Market

Funds

—

0

.7

%

(Cost:

$

1,984,450

)

...............................

1,984,450

Par

(000)

Pa

r

(

000)

U.S.

Treasury

Obligations

—

12.3%

U.S.

Treasury

Bills

,

5.27

%

,

03/14/24

(i)

......

35,425

35,206,886

Total

U.S.

Treasury

Obligations

—

12

.3

%

(Cost:

$

35,208,664

)

...............................

35,206,886

Total

Short-Term

Securities

—

13.0%

(Cost:

$

37,193,114

)

...............................

37,191,336

Total

Investments

Before

Options

Written

and

TBA

Sale

Commitments

—

135

.6

%

(Cost:

$

397,348,013

)

..............................

386,980,610

Total

Options

Written

—

(

0

.1

)

%

(Premium

Received

—

$

(

312,180

)

)

....................

(

294,339

)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

9

(Percentages

shown

are

based

on

Net

Assets)

Security

Par

(000)

Pa

r

(

000)

Value

TBA

Sale

Commitments

Mortgage-Backed

Securities

—

(

1

.8

)

%

Government

National

Mortgage

Association

,

6.00

%

,

02/15/54

(g)

.................

USD

(

5,160

)

$

(

5,238,702

)

Total

TBA

Sale

Commitments

—

(

1

.8

)

%

(Proceeds:

$

(

5,231,958

)

)

...........................

(5,238,702)

Total

Investments

Net

of

Options

Written

and

TBA

Sale

Commitments

—

133

.7

%

(Cost:

$

391,803,875

)

..............................

381,447,569

Liabilities

in

Excess

of

Other

Assets

—

(

33.7

)

%

............

(

96,063,802

)

Net

Assets

—

100.0%

...............................

$

285,383,767

(a)

Step

coupon

security.

Coupon

rate

will

either

increase

(step-up

bond)

or

decrease

(step-down

bond)

at

regular

intervals

until

maturity.

Interest

rate

shown

reflects

the

rate

currently

in

effect.

(b)

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.

(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)

This

security

may

be

resold

to

qualified

foreign

investors

and

foreign

institutional

buyers

under

Regulation

S

of

the

Securities

Act

of

1933.

(e)

Security

is

valued

using

significant

unobservable

inputs

and

is

classified

as

Level

3

in

the

fair

value

hierarchy.

(f)

Zero-coupon

bond.

(g)

Represents

or

includes

a

TBA

transaction.

(h)

Annualized

7-day

yield

as

of

period

end.

(i)

Rates

are

discount

rates

or

a

range

of

discount

rates

as

of

period

end.

For

Fund

compliance

purposes,

the

Fund's

industry

classifications

refer

to

one

or

more

of

the

industry

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

industry

sub-classifications

for

reporting

ease.

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

10

Derivative

Financial

Instruments

Outstanding

as

of

Period

End

Futures

Contracts

Description

Number

of

Contracts

Expiration

Date

Notional

Amount

(000)

Value/

Unrealized

Appreciation

(Depreciation)

Long

Contracts

U.S.

Treasury

10-Year

Ultra

Note

...............................................

8

03/19/24

$

936

$

9,856

U.S.

Treasury

Ultra

Bond

.....................................................

38

03/19/24

4,914

292,946

U.S.

Treasury

2-Year

Note

....................................................

2

03/28/24

411

3,416

306,218

Short

Contracts

3-mo.

SOFR

Interest

Futures

..................................................

2

03/19/24

473

8,050

U.S.

Treasury

10-Year

Note

...................................................

250

03/19/24

28,090

150,770

U.S.

Treasury

Long

Bond

.....................................................

10

03/19/24

1,226

22,211

U.S.

Treasury

5-Year

Note

....................................................

75

03/28/24

8,133

(

161,041

)

3-mo.

SOFR

Interest

Futures

..................................................

2

06/18/24

474

(

428

)

3-mo.

SOFR

Interest

Futures

..................................................

2

09/17/24

477

(

3,078

)

3-mo.

SOFR

Interest

Futures

..................................................

2

12/17/24

479

10

16,494

$

322,712

OTC

Interest

Rate

Swaptions

Written

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Call

10-Year

Interest

Rate

Swap

(a)

4.04%

Semi-Annual

1-day

SOFR

Annual

Goldman

Sachs

International

09/26/24

4

.04

%

USD

2,150

$

(

118,775

)

10-Year

Interest

Rate

Swap

(a)

4.08%

Semi-Annual

1-day

SOFR

Annual

Bank

of

America

NA

09/30/24

4

.08

USD

2,150

(

124,332

)

(

243,107

)

Put

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.04%

Semi-Annual

Goldman

Sachs

International

09/26/24

4

.04

USD

2,150

(

26,146

)

10-Year

Interest

Rate

Swap

(a)

1-day

SOFR

Annual

4.08%

Semi-Annual

Bank

of

America

NA

09/30/24

4

.08

USD

2,150

(

25,086

)

(

51,232

)

$

(

294,339

)

(a)

Forward

settling

swaption.

Centrally

Cleared

Interest

Rate

Swap

s

Paid

by

the

Fund

Received

by

the

Fund

Rate

Frequency

Rate

Frequency

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

1-day

SOFR

Annual

3.99%

Annual

08/10/25

USD

1,200

$

(

14,935

)

$

—

$

(

14,935

)

1-day

SOFR

Annual

4.07%

Annual

08/16/25

USD

7,700

(

81,092

)

—

(

81,092

)

0.18%

Quarterly

1-day

EFFR

Quarterly

10/21/25

USD

159

10,783

—

10,783

1-day

SOFR

Quarterly

0.17%

Quarterly

10/21/25

USD

159

(

10,879

)

—

(

10,879

)

1-day

SOFR

Annual

3.41%

Annual

11/21/25

USD

9,400

(

164,824

)

—

(

164,824

)

1-day

SOFR

Annual

4.15%

Annual

12/13/25

USD

10,300

(

20,338

)

—

(

20,338

)

0.56%

Quarterly

1-day

EFFR

Quarterly

10/21/30

USD

47

8,316

—

8,316

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

11

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

Centrally

Cleared

Interest

Rate

Swaps

(continued)

Paid

by

the

Fund

Received

by

the

Fund

Rate

Frequency

Rate

Frequency

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

1-day

SOFR

Quarterly

0.53%

Quarterly

10/21/30

USD

47

$

(

8,510

)

$

—

$

(

8,510

)

$

(

281,479

)

$

—

$

(

281,479

)

OTC

Credit

Default

Swap

s

—

Buy

Protection

Reference

Obligation/Index

Financing

Rate

Paid

by

the

Fund

Payment

Frequency

Counterparty

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

CMBX.NA.9.BBB-

.........

3

.00

%

Monthly

JPMorgan

Securities

LLC

09/17/58

USD

3,100

$

445,304

$

287,307

$

157,997

$

–

$

–

$

–

OTC

Credit

Default

Swap

s

—

Sell

Protection

Reference

Obligation/Index

Financing

Rate

Received

by

the

Fund

Payment

Frequency

Counterparty

Termination

Date

Credit

Rating

(a)

Notional

Amount

(000)

(b)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

CMBX.NA.9.A

........

2

.00

%

Monthly

Goldman

Sachs

International

09/17/58

A

USD

275

$

(

18,185

)

$

(

4,788

)

$

(

13,397

)

CMBX.NA.9.A

........

2

.00

Monthly

Morgan

Stanley

&

Co.

International

plc

09/17/58

A

USD

275

(

18,185

)

(

4,863

)

(

13,322

)

CMBX.NA.9.BBB-

.....

3

.00

Monthly

Deutsche

Bank

AG

09/17/58

BBB-

USD

2,197

(

315,591

)

(

222,859

)

(

92,732

)

CMBX.NA.9.BBB-

.....

3

.00

Monthly

Goldman

Sachs

International

09/17/58

BBB-

USD

1,012

(

145,370

)

(

40,579

)

(

104,791

)

CMBX.NA.15.BBB-

....

3

.00

Monthly

Morgan

Stanley

&

Co.

International

plc

11/18/64

BBB-

USD

500

(

81,000

)

(

89,861

)

8,861

$

(

578,331

)

$

(

362,950

)

$

(

215,381

)

(a)

Using

the

rating

of

the

issuer

or

the

underlying

securities

of

the

index,

as

applicable,

provided

by

S&P

Global

Ratings.

(b)

The

maximum

potential

amount

the

Fund

may

pay

should

a

negative

credit

event

take

place

as

defined

under

the

terms

of

the

agreement.

The

following

reference

rates,

and

their

values

as

of

period

end,

are

used

for

security

descriptions:

Reference

Index

Reference

Rate

1-day

EFFR

.........................................

Effective

Federal

Funds

Rate

5

.33

%

1-day

SOFR

.........................................

Secured

Overnight

Financing

Rate

5

.33

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2024

BlackRock

U.S.

Mortgage

Portfolio

12

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.

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

Asset-Backed

Securities

...................................

$

—

$

48,843,074

$

—

$

48,843,074

Corporate

Bonds

........................................

—

450,052

—

450,052

Non-Agency

Mortgage-Backed

Securities

........................

—

121,534,631

1,904,729

123,439,360

U.S.

Government

Sponsored

Agency

Securities

....................

—

177,056,788

—

177,056,788

Short-Term

Securities

Money

Market

Funds

......................................

1,984,450

—

—

1,984,450

U.S.

Treasury

Obligations

...................................

—

35,206,886

—

35,206,886

Liabilities

Investments

TBA

Sale

Commitments

....................................

—

(

5,238,702

)

—

(

5,238,702

)

$

1,984,450

$

377,852,729

$

1,904,729

$

381,741,908

Derivative

Financial

Instruments

(a)

Assets

Credit

contracts

...........................................

$

—

$

166,858

$

—

$

166,858

Interest

rate

contracts

.......................................

487,259

19,099

—

506,358

Liabilities

Credit

contracts

...........................................

—

(

224,242

)

—

(

224,242

)

Interest

rate

contracts

.......................................

(

164,547

)

(

594,917

)

—

(

759,464

)

$

322,712

$

(

633,202

)

$

—

$

(

310,490

)

(a)

Derivative

financial

instruments

are

swaps,

futures

contracts

and

options

written.

Swaps

and

futures

contracts

are

valued

at

the

unrealized

appreciation

(depreciation)

on

the

instrument

and

options

written

are

shown

at

value.

Currency

Abbreviation

USD

United

States

Dollar

Portfolio

Abbreviation

CMT

Constant

Maturity

Treasury

CSMC

Credit

Suisse

Mortgage

Capital

CWABS

Countrywide

Asset-Backed

Certificates

EFFR

Effective

Federal

Funds

Rate

LIBOR

London

Interbank

Offered

Rate

OTC

Over-the-counter

REMIC

Real

Estate

Mortgage

Investment

Conduit

SOFR

Secured

Overnight

Financing

Rate

TBA

To-be-announced

Fair

Value

Hierarchy

as

of

Period

End

(continued)