# EDGAR Filing Document

**Accession Number:** 0000742212
**File Stem:** 0001752724-25-192562
**Filing Date:** 2025-8
**Character Count:** 57670
**Document Hash:** 856e12bcb717feaddd4a154934bdc6f2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001752724-25-192562.hdr.sgml**: 20250819

**ACCESSION NUMBER**: 0001752724-25-192562

**CONFORMED SUBMISSION TYPE**: NPORT-P

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250630

**FILED AS OF DATE**: 20250819

**DATE AS OF CHANGE**: 20250819

**PERIOD START**: 20251231

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** NORTHWESTERN MUTUAL SERIES FUND INC
- **CENTRAL INDEX KEY:** 0000742212

**ORGANIZATION NAME:**
- **EIN:** 391603401
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** NPORT-P
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-03990
- **FILM NUMBER:** 251231243

**BUSINESS ADDRESS:**
- **STREET 1:** 720 E WISCONSIN AVE
- **CITY:** MILWAUKEE
- **STATE:** WI
- **ZIP:** 53202
- **BUSINESS PHONE:** 4142992508

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

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** NORTHWESTERN MUTUAL VARIABLE LIFE SERIES FUND INC
- **DATE OF NAME CHANGE:** 19940830

## Series and Classes Contracts Data

### Long-Term US Government Bond Portfolio (Series ID: S000018234)

| Class ID   | Class Name                             | Ticker Symbol   |
|:---|:---|:---|
| C000050282 | Long-Term US Government Bond Portfolio |  |

## Form NPORT-P: Monthly Portfolio Investments Report

### NPORT-P: Part A: General Information

**Item A.1. Information about the Registrant.**

- **a. Name of Registrant:** NORTHWESTERN MUTUAL SERIES FUND INC

- **b. Investment Company Act file number:** 811-03990

- **c. CIK number of Registrant:** 0000742212

- **d. LEI of Registrant:** 549300T1UBX7MDSNZA55

- **e. Address and telephone number of Registrant.**

  - **Street Address 1:** 720 E WISCONSIN AVE

  - **City:** MILWAUKEE

  - **State:** WI

  - **Foreign country:** US

  - **Zip / Postal Code:** 53202

  - **Telephone number:** 414-271-1444

**Item A.2. Information about the Series.**

- **a. Name of Series:** Long-Term US Government Bond Portfolio

- **b. EDGAR series identifier (if any):** S000018234

- **c. LEI of Series:** G1NIKRLT4013DJUHQR28

**Item A.3. Reporting period.**

- **a. Date of fiscal year-end:** 2025-12-31

- **b. Date as of which information is reported:** 2025-06-30

**Item A.4. Final filing**

Does the Fund anticipate that this will be its final filing on Form N-PORT? **No**

### Fund Information

**Total Assets:** $335550522.58

**Total Liabilities:** $213115249.30

**Net Assets:** $122435273.28

**Delayed Delivery Securities:** $211619456.17

**Cash Not Reported:** $1889930.09

**Currency Risk Metrics (dv01):**

- 

**Credit Spread Risk - Investment Grade (dv01):**

- **3-Month:** -2.91000000 | **1-Year:** -311.10000000 | **5-Year:** -234.77000000 | **10-Year:** -8.09000000 | **30-Year:** -0.28000000

**Credit Spread Risk - Non-Investment Grade (dv01):**

- **3-Month:** -0.71000000 | **1-Year:** -76.93000000 | **5-Year:** -295.78000000 | **10-Year:** -573.33000000 | **30-Year:** -133.83000000

**Monthly Return Information**

| Class               | Month 1 Return (%)   | Month 2 Return (%)   | Month 3 Return (%)   |
|:---|:---|:---|:---|
| Class ID C000050282 | -0.95%               | -2.88%               | 2.31%                |

**Monthly Gains & Losses**

| Period   | Net Realized Gain/Loss   | Net Unrealized Appreciation/Depreciation   |
|:---|:---|:---|
| Month 1  | $-1565200.53             | $-342041.65                                |
| Month 2  | $-3837349.58             | $-860530.80                                |
| Month 3  | $-586869.63              | $3580673.87                                |

**Designated Index Information**

- **Index Name:** Bloomberg Long-Term U.S. Treasury Index

- **Index Identifier:** LUTLTRUU

### Schedule of Portfolio Investments

| Name                                           | Title                                                                                                         | Identifiers                                   | Payoff Profile   | Asset Category   | Issuer Category   | Country   |   Balance | Units   | Value (USD)   | % of Net Assets   | Maturity Date   | Coupon Type   | Annualized Rate (%)   | Restricted?   |   Fair Value Level | Lending Status   |
|:---|:---|:---|:---|:---|:---|:---|---:|:---|:---|:---|:---|:---|:---|:---|---:|:---|
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CGQ8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    200000 | PA      | $201945.31    | 0.16%             | 2030-02-28      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TL2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  15830000 | PA      | $13844448.01  | 11.31%            | 2052-11-15      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SE9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1600000 | PA      | $1265687.50   | 1.03%             | 2048-11-15      | Fixed         | 3.38%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CJH5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    628344 | PA      | $651767.03    | 0.53%             | 2028-10-15      | Fixed         | 2.38%                 | No            |                  2 | On Loan: No      |
| Merrill Lynch Mortgage Investors Trust         | Merrill Lynch Mortgage Investors Trust MLMI Series 2003-A4                                                    | CUSIP: 589929W87<br>LEI: 9DJT3UXIJIZJI4WXO774 | Long             | ABS-MBS          | CORP              | US        |       399 | PA      | $389.16       | 0.00%             | 2033-05-25      | Variable      | 7.00%                 | No            |                  2 | On Loan: No      |
| UMBS, TBA                                      | Uniform Mortgage-Backed Security, TBA                                                                         | CUSIP: 01F062689<br>LEI: N/A                  | Long             | ABS-MBS          | USGSE             | US        |   2800000 | PA      | $2886887.64   | 2.36%             | 2054-08-15      | Fixed         | 6.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CJM4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    600000 | PA      | $615515.63    | 0.50%             | 2030-11-30      | Fixed         | 4.38%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CEV9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    400000 | PA      | $392687.50    | 0.32%             | 2029-06-30      | Fixed         | 3.25%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CLX7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    100000 | PA      | $100925.78    | 0.08%             | 2027-11-15      | Fixed         | 4.13%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac Pool                                                                                              | CUSIP: 3132DWLJ0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   1670291 | PA      | $1598213.19   | 1.31%             | 2054-05-01      | Fixed         | 4.50%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association       | Government National Mortgage Association                                                                      | CUSIP: 38377GMM8<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |    135541 | PA      | $113471.52    | 0.09%             | 2035-09-20      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| ECMC Group Student Loan Trust                  | ECMC Group Student Loan Trust 2018-1                                                                          | CUSIP: 26828HAA5<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |     38080 | PA      | $37725.51     | 0.03%             | 2068-02-27      | Floating      | 5.17%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834KP2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |     50000 | PA      | $22724.18     | 0.02%             | 2041-08-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UJ5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    300000 | PA      | $298406.25    | 0.24%             | 2045-02-15      | Fixed         | 4.75%                 | No            |                  2 | On Loan: No      |
| FHLMC STRUCTURED PASS THROUGH                  | Freddie Mac Structured Pass-Through Certificates                                                              | CUSIP: 31395A3J2<br>LEI: 254900HROIFWPRGM1V77 | Long             | ABS-MBS          | USGSE             | US        |      3153 | PA      | $3045.80      | 0.00%             | 2044-07-25      | Floating      | 5.80%                 | No            |                  2 | On Loan: No      |
| Chicago Mercantile Exchange                    | Long: BWU01D5J2 IRS USD R V 12MSOFR SWUV1D5J4 CCPOIS / Short: BWU01D5J2 IRS USD P F  1.75000 SWU01D5J2 CCPOIS | CUSIP: 000000000<br>LEI: SNZ2OJLFK8MNNCLQOF39 | N/A              | DIR              |  | US        |    500000 | OU      | $187202.05    | 0.15%             |  |  |  | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CJY8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2400625 | PA      | $2379608.03   | 1.94%             | 2034-01-15      | Fixed         | 1.75%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae REMICS                                                                                             | CUSIP: 3136A76U1<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |     21232 | PA      | $20979.62     | 0.02%             | 2042-09-25      | Floating      | 4.92%                 | No            |                  2 | On Loan: No      |
| VESSEL MANAGEMENT SERVIC                       | Vessel Management Services Inc                                                                                | CUSIP: 228027AA6<br>LEI: 549300FGG4OD84UNFA43 | Long             | DBT              | CORP              | US        |    319000 | PA      | $286755.81    | 0.23%             | 2036-08-15      | Fixed         | 3.43%                 | No            |                  2 | On Loan: No      |
| Freddie Mac Military Housing Bonds Resec Trust | Freddie Mac Military Housing Bonds Resecuritization Trust Certificates 2015-R1                                | CUSIP: 35563CAJ7<br>LEI: 549300ZG8WH0M4JSUM77 | Long             | ABS-MBS          | USGSE             | US        |    543702 | PA      | $448662.12    | 0.37%             | 2052-10-25      | Variable      | 4.31%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SW9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1900000 | PA      | $1306843.75   | 1.07%             | 2041-02-15      | Fixed         | 1.88%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CDL2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    700000 | PA      | $650589.84    | 0.53%             | 2028-11-30      | Fixed         | 1.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TM0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2800000 | PA      | $2554453.13   | 2.09%             | 2042-11-15      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CGK1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2304973 | PA      | $2202483.15   | 1.80%             | 2033-01-15      | Fixed         | 1.13%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RK6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1440000 | PA      | $1013737.51   | 0.83%             | 2045-02-15      | Fixed         | 2.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TQ1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    300000 | PA      | $268546.88    | 0.22%             | 2043-02-15      | Fixed         | 3.88%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SL3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  12920000 | PA      | $7586462.50   | 6.20%             | 2050-02-15      | Fixed         | 2.00%                 | No            |                  2 | On Loan: No      |
| Hilton USA Trust                               | Hilton USA Trust 2016-HHV                                                                                     | CUSIP: 43300LAA8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    600000 | PA      | $589930.44    | 0.48%             | 2038-11-05      | Fixed         | 3.72%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SC3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2430000 | PA      | $1843667.58   | 1.51%             | 2048-05-15      | Fixed         | 3.13%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US LONG BOND(CBT) SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       -74 | NC      | $-374733.78   | -0.31%            |  |  |  | No            |                  1 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 3137BD4R4<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |    621775 | PA      | $506022.84    | 0.41%             | 2053-04-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834LX4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |     50000 | PA      | $21103.87     | 0.02%             | 2042-11-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UF3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   3300000 | PA      | $3230390.63   | 2.64%             | 2044-11-15      | Fixed         | 4.63%                 | No            |                  2 | On Loan: No      |
| Towd Point Mortgage Trust                      | Towd Point Mortgage Trust 2020-1                                                                              | CUSIP: 89178WBB3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    200000 | PA      | $182276.04    | 0.15%             | 2060-01-25      | Variable      | 3.10%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UL0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    500000 | PA      | $513593.75    | 0.42%             | 2045-05-15      | Fixed         | 5.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SH2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1750000 | PA      | $1256240.23   | 1.03%             | 2049-05-15      | Fixed         | 2.88%                 | No            |                  2 | On Loan: No      |
| Extended Stay America Trust                    | Extended Stay America Trust 2021-ESH                                                                          | CUSIP: 30227FAA8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    343091 | PA      | $343198.32    | 0.28%             | 2038-07-15      | Floating      | 5.51%                 | No            |                  2 | On Loan: No      |
| TENN VALLEY AUTH                               | Tennessee Valley Authority Principal Strip                                                                    | CUSIP: 88059FBG5<br>LEI: 549300HE1ISW43LNKM54 | Long             | DBT              | USGA              | US        |    500000 | PA      | $414563.94    | 0.34%             | 2030-05-01      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UB2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    500000 | PA      | $490332.03    | 0.40%             | 2044-05-15      | Fixed         | 4.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RP5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    370000 | PA      | $281879.30    | 0.23%             | 2045-11-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 3137AT2J0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   2200000 | PA      | $2117961.34   | 1.73%             | 2032-08-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae REMICS                                                                                             | CUSIP: 31396VSR0<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |     20521 | PA      | $20289.13     | 0.02%             | 2037-05-25      | Fixed         | 4.25%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SX7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2300000 | PA      | $1458433.59   | 1.19%             | 2051-05-15      | Fixed         | 2.38%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TN8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   2900000 | PA      | $2367351.55   | 1.93%             | 2053-02-15      | Fixed         | 3.63%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 10YR FUT OPTN AUG25P 109                                                                                   | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       -19 | NC      | $-593.75      | -0.00%            |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RM2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1410000 | PA      | $1080026.95   | 0.88%             | 2045-05-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TK4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   9500000 | PA      | $7973691.43   | 6.51%             | 2042-08-15      | Fixed         | 3.38%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 3137BDY34<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   1895815 | PA      | $1841216.14   | 1.50%             | 2044-09-15      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association       | Government National Mortgage Association                                                                      | CUSIP: 38376VKK2<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |    215574 | PA      | $170628.19    | 0.14%             | 2040-02-20      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| UMBS, TBA                                      | Uniform Mortgage-Backed Security, TBA                                                                         | CUSIP: 01F060675<br>LEI: N/A                  | Long             | ABS-MBS          | USGSE             | US        |   3100000 | PA      | $3149980.80   | 2.57%             | 2054-07-15      | Fixed         | 6.00%                 | No            |                  2 | On Loan: No      |
| RESOLUTION FUNDING STRIP                       | Resolution Funding Corp Interest Strip                                                                        | CUSIP: 76116EHK9<br>LEI: N/A                  | Long             | DBT              | USGA              | US        |    400000 | PA      | $358868.73    | 0.29%             | 2028-04-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| Hertz Vehicle Financing LLC                    | Hertz Vehicle Financing LLC                                                                                   | CUSIP: 42806MAN9<br>LEI: 5493004IHDYOZ9K9WF47 | Long             | ABS-O            | CORP              | US        |    300000 | PA      | $288075.00    | 0.24%             | 2028-06-26      | Fixed         | 2.33%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SD1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1500000 | PA      | $1109355.47   | 0.91%             | 2048-08-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 3137A2SY8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |     13893 | PA      | $13753.85     | 0.01%             | 2040-11-15      | Floating      | 4.92%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834LR7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    220000 | PA      | $94135.73     | 0.08%             | 2042-08-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CHZ7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    300000 | PA      | $311285.16    | 0.25%             | 2030-09-30      | Fixed         | 4.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SJ8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    300000 | PA      | $188191.41    | 0.15%             | 2049-08-15      | Fixed         | 2.25%                 | No            |                  2 | On Loan: No      |
| UMBS, TBA                                      | Uniform Mortgage-Backed Security, TBA                                                                         | CUSIP: 01F050684<br>LEI: N/A                  | Long             | ABS-MBS          | USGSE             | US        |   1300000 | PA      | $1273260.83   | 1.04%             | 2054-08-15      | Fixed         | 5.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TR9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1400000 | PA      | $1141875.00   | 0.93%             | 2053-05-15      | Fixed         | 3.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TZ1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    400000 | PA      | $386500.00    | 0.32%             | 2044-02-15      | Fixed         | 4.50%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                       | Benchmark 2019-B9 Mortgage Trust                                                                              | CUSIP: 08160JAE7<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    600000 | PA      | $584039.22    | 0.48%             | 2052-03-15      | Fixed         | 4.02%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834KH0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |     40000 | PA      | $18450.48     | 0.02%             | 2041-05-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| Chicago Mercantile Exchange                    | Long: BWU025U84 IRS USD R V 12MSOFR SWUV25U86 CCPOIS / Short: BWU025U84 IRS USD P F  3.50000 SWU025U84 CCPOIS | CUSIP: 000000000<br>LEI: SNZ2OJLFK8MNNCLQOF39 | N/A              | DIR              |  | US        |   2800000 | OU      | $209023.36    | 0.17%             |  |  |  | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CJG7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    200000 | PA      | $209945.31    | 0.17%             | 2030-10-31      | Fixed         | 4.88%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 5YR NOTE (CBT) SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |      -101 | NC      | $-99547.32    | -0.08%            |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TS7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   3100000 | PA      | $2768929.67   | 2.26%             | 2043-05-15      | Fixed         | 3.88%                 | No            |                  2 | On Loan: No      |
| Government National Mortgage Association       | Ginnie Mae                                                                                                    | CUSIP: 21H040673<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |    800000 | PA      | $743696.23    | 0.61%             | 2054-07-20      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 31394RLM9<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |     75463 | PA      | $78209.13     | 0.06%             | 2034-02-15      | Fixed         | 5.50%                 | No            |                  2 | On Loan: No      |
| COMM Mortgage Trust                            | COMM 2018-HOME Mortgage Trust                                                                                 | CUSIP: 20048JAA8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    200000 | PA      | $194100.80    | 0.16%             | 2033-04-10      | Variable      | 3.94%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TU2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1600000 | PA      | $1525062.50   | 1.25%             | 2043-08-15      | Fixed         | 4.38%                 | No            |                  2 | On Loan: No      |
| UMBS, TBA                                      | Uniform Mortgage-Backed Security, TBA                                                                         | CUSIP: 01F060683<br>LEI: N/A                  | Long             | ABS-MBS          | USGSE             | US        |   3700000 | PA      | $3756330.28   | 3.07%             | 2054-08-15      | Fixed         | 6.00%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 10YR NOTE (CBT)SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |        68 | NC      | $129529.80    | 0.11%             |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SR0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1650000 | PA      | $1025835.94   | 0.84%             | 2040-05-15      | Fixed         | 1.13%                 | No            |                  2 | On Loan: No      |
| Massachusetts Educational Financing Authority  | Massachusetts Educational Financing Authority                                                                 | CUSIP: 57563NAA6<br>LEI: 5493007K5OP7V6CL0Y88 | Long             | ABS-O            | CORP              | US        |      9506 | PA      | $9518.56      | 0.01%             | 2038-04-25      | Floating      | 5.57%                 | No            |                  2 | On Loan: No      |
| LCH Ltd.                                       | Long: BWU01UNW5 IRS USD R V 03MSOFR SWUV1UNW7 CCPOIS / Short: BWU01UNW5 IRS USD P F  1.25000 SWU01UNW5 CCPOIS | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |   3110000 | OU      | $1091173.04   | 0.89%             |  |  |  | No            |                  2 | On Loan: No      |
| Chicago Mercantile Exchange                    | Long: SWU01PG53 IRS USD R F  1.00000 SWU01PG53 CCPOIS / Short: SWU01PG53 IRS USD P V 03MSOFR SWUV1PG55 CCPOIS | CUSIP: 000000000<br>LEI: SNZ2OJLFK8MNNCLQOF39 | N/A              | DIR              |  | US        |   3170000 | OU      | $-50507.61    | -0.04%            |  |  |  | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CGW5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1925352 | PA      | $1921728.97   | 1.57%             | 2028-04-15      | Fixed         | 1.25%                 | No            |                  2 | On Loan: No      |
| Structured Asset Mortgage Investments Inc      | Structured Asset Mortgage Investments II Trust 2004-AR5                                                       | CUSIP: 86359LDX4<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |       948 | PA      | $907.21       | 0.00%             | 2034-10-19      | Floating      | 5.09%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US ULTRA BOND CBT SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |        -4 | NC      | $-6526.88     | -0.01%            |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TJ7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   4500000 | PA      | $3248261.73   | 2.65%             | 2052-08-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 3138L8YJ7<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |    505792 | PA      | $474103.24    | 0.39%             | 2040-02-01      | Fixed         | 3.60%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SQ2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  44690000 | PA      | $27493078.40  | 22.46%            | 2040-08-15      | Fixed         | 1.13%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RQ3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    850000 | PA      | $589023.44    | 0.48%             | 2046-02-15      | Fixed         | 2.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CEE7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    900000 | PA      | $857531.25    | 0.70%             | 2029-03-31      | Fixed         | 2.38%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SF6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  10470000 | PA      | $7714263.33   | 6.30%             | 2049-02-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 31402RFV6<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |     14926 | PA      | $15129.42     | 0.01%             | 2035-06-01      | Fixed         | 5.00%                 | No            |                  2 | On Loan: No      |
| US TREASURY N/B                                | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RJ9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1620000 | PA      | $1247463.28   | 1.02%             | 2044-11-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810RH3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1620000 | PA      | $1277332.03   | 1.04%             | 2044-08-15      | Fixed         | 3.13%                 | No            |                  2 | On Loan: No      |
| Freddie Mac                                    | Freddie Mac REMICS                                                                                            | CUSIP: 3137BERC0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |    918633 | PA      | $827730.11    | 0.68%             | 2054-09-15      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| BENCHMARK Mortgage Trust                       | Benchmark 2024-V6 Mortgage Trust                                                                              | CUSIP: 081927AB1<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |    200000 | PA      | $208668.04    | 0.17%             | 2057-03-15      | Fixed         | 5.93%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CHW4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    200000 | PA      | $202890.62    | 0.17%             | 2030-08-31      | Fixed         | 4.13%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CHF1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    200000 | PA      | $199554.69    | 0.16%             | 2030-05-31      | Fixed         | 3.75%                 | No            |                  2 | On Loan: No      |
| Chicago Mercantile Exchange                    | Long: SWU01D5I4 IRS USD R F  1.60000 SWU01D5I4 CCPOIS / Short: SWU01D5I4 IRS USD P V 12MSOFR SWUV1D5I6 CCPOIS | CUSIP: 000000000<br>LEI: SNZ2OJLFK8MNNCLQOF39 | N/A              | DIR              |  | US        |   7580000 | OU      | $-424290.50   | -0.35%            |  |  |  | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 9128334Y3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    850000 | PA      | $572821.72    | 0.47%             | 2034-08-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| US TREASURY N/B                                | U.S. Treasury Bonds                                                                                           | CUSIP: 912810QZ4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    600000 | PA      | $482507.81    | 0.39%             | 2043-02-15      | Fixed         | 3.13%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 10YR FUT OPTN AUG25C 112.5                                                                                 | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       -19 | NC      | $-10093.75    | -0.01%            |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UK2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    900000 | PA      | $894937.50    | 0.73%             | 2055-05-15      | Fixed         | 4.75%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SP4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1080000 | PA      | $532490.63    | 0.43%             | 2050-08-15      | Fixed         | 1.38%                 | No            |                  2 | On Loan: No      |
| New Residential Mortgage Loan Trust            | New Residential Mortgage Loan Trust 2020-RPL1                                                                 | CUSIP: 64828XAA1<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |     66638 | PA      | $63791.35     | 0.05%             | 2059-11-25      | Variable      | 2.75%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 01F040685<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |    700000 | PA      | $650726.74    | 0.53%             | 2049-08-13      | Fixed         | 4.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CEZ0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1766384 | PA      | $1647550.29   | 1.35%             | 2032-07-15      | Fixed         | 0.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SA7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    330000 | PA      | $245192.58    | 0.20%             | 2048-02-15      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UD8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1600000 | PA      | $1465812.50   | 1.20%             | 2044-08-15      | Fixed         | 4.13%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae REMICS                                                                                             | CUSIP: 3136ATQS6<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |    900000 | PA      | $754380.90    | 0.62%             | 2046-09-25      | Fixed         | 3.00%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 31403C6L0<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |     23862 | PA      | $24211.29     | 0.02%             | 2036-02-01      | Fixed         | 5.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Inflation-Indexed Notes                                                                         | CUSIP: 91282CDX6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    925712 | PA      | $838982.16    | 0.69%             | 2032-01-15      | Fixed         | 0.13%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810UG1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  10900000 | PA      | $10610468.75  | 8.67%             | 2055-02-15      | Fixed         | 4.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810ST6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   9800000 | PA      | $6243289.04   | 5.10%             | 2040-11-15      | Fixed         | 1.38%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 2YR NOTE (CBT) SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |        -8 | NC      | $-7385.40     | -0.01%            |  |  |  | No            |                  1 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 31418E5R7<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |    881169 | PA      | $910116.37    | 0.74%             | 2054-05-01      | Fixed         | 6.50%                 | No            |                  2 | On Loan: No      |
| Fannie Mae                                     | Fannie Mae Pool                                                                                               | CUSIP: 31418DDL3<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |     19171 | PA      | $19501.58     | 0.02%             | 2049-05-01      | Fixed         | 5.50%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CHJ3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    400000 | PA      | $398984.38    | 0.33%             | 2030-06-30      | Fixed         | 3.75%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834KV9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |     80000 | PA      | $35798.19     | 0.03%             | 2041-11-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| Chicago Board of Trade                         | US 10YR ULTRA FUT SEP25                                                                                       | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |      -190 | NC      | $-481203.50   | -0.39%            |  |  |  | No            |                  1 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810QQ4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  16080000 | PA      | $15583153.08  | 12.73%            | 2041-05-15      | Fixed         | 4.38%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Notes                                                                                           | CUSIP: 91282CGS4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    200000 | PA      | $198570.31    | 0.16%             | 2030-03-31      | Fixed         | 3.63%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury STRIPS Coupon                                                                                   | CUSIP: 912834LK2<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |     70000 | PA      | $30386.30     | 0.02%             | 2042-05-15      | None          | 0.00%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810TW8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   1790000 | PA      | $1788112.10   | 1.46%             | 2043-11-15      | Fixed         | 4.75%                 | No            |                  2 | On Loan: No      |
| United States Treasury                         | U.S. Treasury Bonds                                                                                           | CUSIP: 912810SS8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |    400000 | PA      | $210734.38    | 0.17%             | 2050-11-15      | Fixed         | 1.63%                 | No            |                  2 | On Loan: No      |

### Signature

**Date Signed:** 2025-07-18

**Name of Applicant:** NORTHWESTERN MUTUAL SERIES FUND INC

**Signature:** Linda Wisniewski

**Name of Signer:** Linda Wisniewski

**Title:** Controller and Chief Accounting Officer