# EDGAR Filing Document

**Accession Number:** 0001167711
**File Stem:** 0001167711-26-000004
**Filing Date:** 2026-5
**Character Count:** 8525
**Document Hash:** 43f521b322d180b583c3123685be51e1
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001167711-26-000004.hdr.sgml**: 20260507

**ACCESSION NUMBER**: 0001167711-26-000004

**CONFORMED SUBMISSION TYPE**: 13F-HR

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260331

**FILED AS OF DATE**: 20260507

**DATE AS OF CHANGE**: 20260506

**EFFECTIVENESS DATE**: 20260507

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MASON STREET ADVISORS, LLC
- **CENTRAL INDEX KEY:** 0001167711

**ORGANIZATION NAME:**
- **EIN:** 392035564
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 13F-HR
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 028-10206
- **FILM NUMBER:** 26950408

**BUSINESS ADDRESS:**
- **STREET 1:** 720 EAST WISCONSIN AVE
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202
- **BUSINESS PHONE:** 4146655400

**MAIL ADDRESS:**
- **STREET 1:** 720 EAST WISCONSIN AVE
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MASON STREET ADVISORS LLC
- **DATE OF NAME CHANGE:** 20020219

### FORM 13F COVER PAGE

**Report for the Calendar Year or Quarter Ended:** 03-31-2026

**Check here if Amendment** [ ] **Amendment Number:** 

**This Amendment (Check only one.):** [ ] is a restatement.

[ ] adds new holdings entries.

**Institutional Investment Manager Filing this Report:**

**Name:** MASON STREET ADVISORS LLC<br>**Address:** 720 EAST WISCONSIN AVE<br>MILWAUKEE, WI 53202

**Form 13F File Number:** 028-10206

**CRD Number (if applicable):** 000114085

**SEC File Number (if applicable):** 801-60721

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.

**Person Signing this Report on Behalf of Reporting Manager:**

**Name:** Andrew Heistad<br>**Title:** Vice President-Treasurer<br>**Phone:** 414 665-1704

**Signature, Place, and Date of Signing:**

/s/Andrew Heistad  MILWAUKEE, WI  05-06-2026<br>[Signature]  [City, State]  [Date]

**Report Type (Check only one.):**

[ ] **13F HOLDINGS REPORT.** (Check here if all holdings of this reporting manager are reported in this report.)

[ ] **13F NOTICE.** (Check here if no holdings are reported in this report, and all holdings are reported by other reporting manager(s).)

[x] **13F COMBINATION REPORT.** (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)

### Form 13F Summary Page

**Report Summary:**

**Number of Other Included Managers:** 0

**Form 13F Information Table Entry Total:** 15

**Form 13F Information Table Value Total:** $1023197016

      (round to nearest dollar)

**List of Other Included Managers:**

Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.

[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]

|   No. | Name                                             | Form 13F File Number   |   CRD Number | SEC File Number   |
|---:|:---|:---|---:|:---|
|     1 | abrdn Investments Ltd                            | 028-14936              |    000162309 | 801-75074         |
|     2 | ALLSPRING GLOBAL INVESTMENTS LLC                 | 028-04413              |    000104973 | 801-21122         |
|     3 | AMERICAN CENTURY INVESTMENT MANAGEMENT INC       | 028-01091              |    000105778 | 801-8174          |
|     4 | BLACKROCK ADVISORS LLC                           | 028-04295              |    000106614 | 801-47710         |
|     5 | Boston Partners                                  | 028-12484              |    000124982 | 801-61786         |
|     6 | DODGE  COX                                       | 028-00400              |    000104596 | 801-1895          |
|     7 | DRIEHAUS CAPITAL MANAGEMENT LLC                  | 028-04207              |    000105757 | 801-18439         |
|     8 | EARNEST PARTNERS LLC                             | 028-05269              |    000107926 | 801-56189         |
|     9 | FEDERATED INVESTMENT MANAGEMENT CO               | 028-04377              |    000105138 | 801-34612         |
|    10 | FIAM LLC                                         | 028-12282              |    000133196 | 801-63658         |
|    11 | FRANKLIN MUTUAL ADVISERS LLC                     | 028-06154              |    000111376 | 801-53068         |
|    12 | FRANKLIN RESOURCES INC                           | 028-00734              |    000106625 | 801-53068         |
|    13 | Invesco Advisers Inc.                            | 028-00255              |    000105360 | 801-33949         |
|    14 | J.P. Morgan Investment Management Inc.           | 028-11937              |    000107038 | 801-21011         |
|    15 | KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC | 028-05792              |    000104599 | 801-24241         |
|    16 | LOOMIS SAYLES  CO L P                            | 028-00398              |    000105377 | 801-170           |
|    17 | MASSACHUSETTS FINANCIAL SERVICES CO /MA/         | 028-04968              |    000110045 | 801-17352         |
|    18 | Neuberger Berman Investment Advisers LLC         | 028-17085              |    000124687 | 801-61757         |
|    19 | Northern Trust Investments Inc                   | 028-10487              |    000105780 | 801-33358         |
|    20 | PACIFIC INVESTMENT MANAGEMENT CO LLC             | 028-10952              |    000104559 | 801-48187         |
|    21 | T. Rowe Price Investment Management Inc.         | 028-22690              |    000314590 | 801-121434        |
|    22 | Vaughan Nelson Investment Management L.P.        | 028-05840              |    000106975 | 801-51795         |
|    23 | WELLINGTON MANAGEMENT GROUP LLP                  | 028-04557              |    000106595 | 801-15908         |
|    24 | PRICE T ROWE ASSOCIATES INC /MD/                 | 028-00115              |    000105496 | 801-856           |

### FORM 13F INFORMATION TABLE

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| NAME OF ISSUER | TITLE OF CLASS | CUSIP | FIGI | VALUE (x$1000) | SHRS OR PRN AMT | SH/PRN | PUT/CALL | INVESTMENT DISCRETION | OTHER MANAGER | VOTING AUTHORITY | VOTING AUTHORITY | VOTING AUTHORITY |
| NAME OF ISSUER | TITLE OF CLASS | CUSIP | FIGI | VALUE (x$1000) | SHRS OR PRN AMT | SH/PRN | PUT/CALL | INVESTMENT DISCRETION | OTHER MANAGER | SOLE | SHARED | NONE |
| ABRDN ETFS | BBRG ALL COMD K1 | 003261104 |  | 8655377 | 356335 | SH |  | DFND | 1 | 356335 | 0 | 0 |
| DIMENSIONAL ETF TRUST | INTERNATNAL VAL | 25434V807 |  | 21286966 | 403315 | SH |  | DFND | 1 | 403315 | 0 | 0 |
| INVESCO EXCHANGE TRADED FD T | S EQL WGT | 46137V357 |  | 51400014 | 267820 | SH |  | DFND | 1 | 267820 | 0 | 0 |
| ISHARES INC | CORE MSCI EMKT | 46434G103 |  | 3035520 | 43520 | SH |  | DFND | 1 | 43520 | 0 | 0 |
| ISHARES TR | CORE MSCI EAFE | 46432F842 |  | 64366558 | 710997 | SH |  | DFND | 1 | 710997 | 0 | 0 |
| ISHARES TR | CORE S ETF | 464287200 |  | 138272146 | 211681 | SH |  | DFND | 1 | 211681 | 0 | 0 |
| ISHARES TR | CORE US AGGBD ET | 464287226 |  | 302700338 | 3049263 | SH |  | DFND | 1 | 3049263 | 0 | 0 |
| ISHARES TR | MSCI INTL QUALTY | 46434V456 |  | 35547634 | 768930 | SH |  | DFND | 1 | 768930 | 0 | 0 |
| ISHARES TR | MSCI USA VALUE | 46432F388 |  | 40979158 | 288200 | SH |  | DFND | 1 | 288200 | 0 | 0 |
| J P MORGAN EXCHANGE TRADED F | ULTRA SHRT ETF | 46641Q837 |  | 24613465 | 486336 | SH |  | DFND | 1 | 486336 | 0 | 0 |
| SCHWAB STRATEGIC TR | US REIT ETF | 808524847 |  | 35375226 | 1646125 | SH |  | DFND | 1 | 1646125 | 0 | 0 |
| SPDR SERIES TRUST | STATE STREET SPD | 78464A664 |  | 105166336 | 3998720 | SH |  | DFND | 1 | 3998720 | 0 | 0 |
| SPDR SERIES TRUST | STATE STREET SPD | 78464A847 |  | 92499804 | 1561969 | SH |  | DFND | 1 | 1561969 | 0 | 0 |
| SPDR SERIES TRUST | STATE STREET SPD | 78464A607 |  | 35205715 | 348675 | SH |  | DFND | 1 | 348675 | 0 | 0 |
| SPDR SERIES TRUST | STATE STREET SPD | 78468R853 |  | 64092759 | 1326423 | SH |  | DFND | 1 | 1326423 | 0 | 0 |

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