# EDGAR Filing Document

**Accession Number:** 0000063075
**File Stem:** 0001410368-25-041614
**Filing Date:** 2025-12
**Character Count:** 52756
**Document Hash:** 14b9563c9d34612df6a4d5a882da5ec5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001410368-25-041614.hdr.sgml**: 20251223

**ACCESSION NUMBER**: 0001410368-25-041614

**CONFORMED SUBMISSION TYPE**: NPORT-P

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251031

**FILED AS OF DATE**: 20251223

**DATE AS OF CHANGE**: 20251223

**PERIOD START**: 20251031

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS SERIES TRUST IX
- **CENTRAL INDEX KEY:** 0000063075

**ORGANIZATION NAME:**
- **EIN:** 042535629
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0430

**FILING VALUES:**
- **FORM TYPE:** NPORT-P
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-02464
- **FILM NUMBER:** 251595616

**BUSINESS ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199
- **BUSINESS PHONE:** 18006372929

**MAIL ADDRESS:**
- **STREET 1:** 111 HUNTINGTON AVENUE
- **STREET 2:** 21ST FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02199

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS SERIES TRUST IX /MA/
- **DATE OF NAME CHANGE:** 19951218

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS SERIES TRUST IX
- **DATE OF NAME CHANGE:** 19950207

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS BOND FUND
- **DATE OF NAME CHANGE:** 19930408

## Series and Classes Contracts Data

### MFS Inflation-Adjusted Bond Fund (Series ID: S000002493)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000006724 | A            | MIAAX           |
| C000006725 | R4           | MIAJX           |
| C000006726 | B            | MIABX           |
| C000006727 | C            | MIACX           |
| C000006728 | I            | MIAIX           |
| C000006730 | R1           | MIALX           |
| C000006732 | R2           | MIATX           |
| C000006733 | R3           | MIAHX           |
| C000126364 | R6           | MIAKX           |

## Form NPORT-P: Monthly Portfolio Investments Report

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

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

- **a. Name of Registrant:** MFS SERIES TRUST IX

- **b. Investment Company Act file number:** 811-02464

- **c. CIK number of Registrant:** 0000063075

- **d. LEI of Registrant:** 549300IJONSVWD5I9F62

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

  - **Street Address 1:** 111 HUNTINGTON AVENUE

  - **City:** BOSTON

  - **State:** MA

  - **Foreign country:** US

  - **Zip / Postal Code:** 02199

  - **Telephone number:** 617-954-5000

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

- **a. Name of Series:** MFS Inflation-Adjusted Bond Fund

- **b. EDGAR series identifier (if any):** S000002493

- **c. LEI of Series:** VOHO802M9IKG3IZTEN75

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

- **a. Date of fiscal year-end:** 2025-10-31

- **b. Date as of which information is reported:** 2025-10-31

**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:** $1562752066.72

**Total Liabilities:** $475218.26

**Net Assets:** $1562276848.46

**Cash Not Reported:** $670.59

**Currency Risk Metrics (dv01):**

- 

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

- **3-Month:** -230.76000000 | **1-Year:** -4102.83000000 | **5-Year:** -3093.15000000 | **10-Year:** -21.09000000 | **30-Year:** 0.00000000

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

- **3-Month:** -127.80000000 | **1-Year:** -1118.56000000 | **5-Year:** -1988.95000000 | **10-Year:** -512.47000000 | **30-Year:** -104.46000000

**Monthly Return Information**

| Class               | Month 1 Return (%)   | Month 2 Return (%)   | Month 3 Return (%)   |
|:---|:---|:---|:---|
| Class ID C000006724 | 1.76%                | 0.19%                | 0.22%                |
| Class ID C000006725 | 1.65%                | 0.23%                | 0.33%                |
| Class ID C000006726 | 1.66%                | 0.14%                | 0.22%                |
| Class ID C000006727 | 1.67%                | 0.07%                | 0.22%                |
| Class ID C000006728 | 1.76%                | 0.23%                | 0.22%                |
| Class ID C000006730 | 1.68%                | 0.09%                | 0.22%                |
| Class ID C000006732 | 1.66%                | 0.20%                | 0.22%                |
| Class ID C000006733 | 1.65%                | 0.27%                | 0.22%                |
| Class ID C000126364 | 1.64%                | 0.25%                | 0.33%                |

**Monthly Gains & Losses**

| Period   | Net Realized Gain/Loss   | Net Unrealized Appreciation/Depreciation   |
|:---|:---|:---|
| Month 1  | $73152.07                | $17266467.75                               |
| Month 2  | $-5104.67                | $531310.98                                 |
| Month 3  | $307113.49               | $-638338.65                                |

**Designated Index Information**

- **Index Name:** BBG US Treasury Infl Prot Sec Idx

- **Index Identifier:** LBUTTRUU

### 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   |
|:---|:---|:---|:---|:---|:---|:---|---:|:---|:---|:---|:---|:---|:---|:---|:---|:---|
| Alinea CLO LTD                                   | Alinea CLO 2018-1 Ltd                                                                                                                  | CUSIP: 016269AE2<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |     53384 | PA      | $53402.16     | 0.00%             | 2031-07-20      | Floating      | 4.78%                 | Yes           | 2                  | On Loan: No      |
| AmeriCredit Automobile Receivables Trust         | AmeriCredit Automobile Receivables Trust 2024-1                                                                                        | CUSIP: 023947AC8<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    600087 | PA      | $600265.18    | 0.04%             | 2028-02-18      | Floating      | 4.78%                 | No            | 2                  | On Loan: No      |
| AREIT CRE Trust                                  | AREIT 2022-CRE6 Trust                                                                                                                  | CUSIP: 04002VAC5<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   2462500 | PA      | $2453263.24   | 0.16%             | 2037-01-20      | Floating      | 5.83%                 | Yes           | 2                  | On Loan: No      |
| ARI Fleet Lease Trust                            | ARI Fleet Lease Trust 2025-A                                                                                                           | CUSIP: 04033CAB2<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1437000 | PA      | $1439648.39   | 0.09%             | 2034-01-17      | Fixed         | 4.38%                 | Yes           | 2                  | On Loan: No      |
| Barclays Commercial Mortgage Securities LLC      | BBCMS Mortgage Trust 2021-C9                                                                                                           | CUSIP: 05493EAZ5<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   7801054 | PA      | $495130.55    | 0.03%             | 2054-02-15      | Variable      | 1.57%                 | No            | 2                  | On Loan: No      |
| Barclays Commercial Mortgage Securities LLC      | BBCMS Trust 2021-C10                                                                                                                   | CUSIP: 05551VBK8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  12255777 | PA      | $611957.90    | 0.04%             | 2054-07-15      | Variable      | 1.21%                 | No            | 2                  | On Loan: No      |
| Bank                                             | BANK 2021-BNK31                                                                                                                        | CUSIP: 06541ABM1<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  18881025 | PA      | $988021.39    | 0.06%             | 2054-02-15      | Variable      | 1.28%                 | No            | 2                  | On Loan: No      |
| Babson CLO Ltd                                   | Barings Clo Ltd 2021-III                                                                                                               | CUSIP: 06762TAN1<br>LEI: 549300V1VT2NXKFG0H98 | Long             | ABS-CBDO         | CORP              | KY        |   3000000 | PA      | $2997267.00   | 0.19%             | 2035-01-18      | Floating      | 5.51%                 | Yes           | 2                  | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B23 Mortgage Trust                                                                                                      | CUSIP: 08162RAF4<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  25093024 | PA      | $1173962.09   | 0.08%             | 2054-02-15      | Variable      | 1.25%                 | No            | 2                  | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B24 Mortgage Trust                                                                                                      | CUSIP: 08163CBE8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  15331697 | PA      | $601658.71    | 0.04%             | 2054-03-15      | Variable      | 1.13%                 | No            | 2                  | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B28 Mortgage Trust                                                                                                      | CUSIP: 08163GAZ3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  24690148 | PA      | $1237354.16   | 0.08%             | 2054-08-15      | Variable      | 1.24%                 | No            | 2                  | On Loan: No      |
| BENCHMARK Mortgage Trust                         | Benchmark 2021-B27 Mortgage Trust                                                                                                      | CUSIP: 08163HAG3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  20359109 | PA      | $1005672.78   | 0.06%             | 2054-07-15      | Variable      | 1.23%                 | No            | 2                  | On Loan: No      |
| Bridgecrest Lending Auto Securitization Trust    | Bridgecrest Lending Auto Securitization Trust 2025-1                                                                                   | CUSIP: 10806HAB3<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1126296 | PA      | $1126419.93   | 0.07%             | 2027-09-15      | Fixed         | 4.71%                 | No            | 2                  | On Loan: No      |
| Colorado Health Facilities Authority             | COLORADO ST HLTH FACS AUTH REVENUE                                                                                                     | CUSIP: 19648FRX4<br>LEI: 5493002JB6DRFRZPEQ21 | Long             | DBT              | MUN               | US        |    600000 | PA      | $591184.56    | 0.04%             | 2026-12-01      | Fixed         | 2.80%                 | No            | 2                  | On Loan: No      |
| CONSERVATION FUND                                | Conservation Fund A Nonprofit Corp/The                                                                                                 | CUSIP: 20848FAA8<br>LEI: N/A                  | Long             | DBT              | CORP              | US        |   1438000 | PA      | $1377504.36   | 0.09%             | 2029-12-15      | Fixed         | 3.47%                 | No            | 2                  | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BBTT9<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   2122790 | PA      | $411836.69    | 0.03%             | 2050-09-25      | Fixed         | 4.00%                 | No            | 2                  | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BQRD3<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   1882659 | PA      | $1904325.76   | 0.12%             | 2053-11-25      | Floating      | 5.63%                 | No            | 2                  | On Loan: No      |
| Fannie Mae                                       | Fannie Mae REMICS                                                                                                                      | CUSIP: 3136BT7D9<br>LEI: B1V7KEBTPIMZEU4LTD58 | Long             | ABS-MBS          | USGSE             | US        |   1304706 | PA      | $1312356.98   | 0.08%             | 2054-12-25      | Floating      | 5.58%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F62R7<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3529812 | PA      | $179284.45    | 0.01%             | 2030-09-25      | Variable      | 1.17%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F9YZ8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   1833583 | PA      | $56220.22     | 0.00%             | 2030-12-25      | Variable      | 0.71%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F9Z38<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   8529316 | PA      | $366332.42    | 0.02%             | 2031-01-25      | Variable      | 0.94%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137F9ZC8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  11388256 | PA      | $416798.78    | 0.03%             | 2031-01-25      | Variable      | 0.78%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FTG43<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   3519182 | PA      | $247471.34    | 0.02%             | 2030-04-25      | Variable      | 1.80%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FUZZ0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   6326494 | PA      | $428742.07    | 0.03%             | 2030-05-25      | Variable      | 1.67%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FV5Q1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   9672915 | PA      | $500892.57    | 0.03%             | 2030-06-25      | Variable      | 1.37%                 | No            | 2                  | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137FXSE9<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   2405585 | PA      | $395123.84    | 0.03%             | 2051-03-25      | Fixed         | 2.50%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FXYZ5<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  54980294 | PA      | $1395724.25   | 0.09%             | 2031-01-25      | Variable      | 0.54%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FXZ50<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  29559520 | PA      | $386526.19    | 0.02%             | 2031-01-25      | Variable      | 0.32%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137FYUL8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  36127540 | PA      | $805626.07    | 0.05%             | 2031-03-25      | Variable      | 0.51%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H13T1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   4421663 | PA      | $257624.66    | 0.02%             | 2031-05-25      | Variable      | 1.21%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H2NA8<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7521262 | PA      | $362302.20    | 0.02%             | 2031-07-25      | Variable      | 0.94%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H3EZ1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   9783880 | PA      | $421187.23    | 0.03%             | 2031-09-25      | Variable      | 0.85%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4BT6<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  32486236 | PA      | $905488.86    | 0.06%             | 2031-09-25      | Variable      | 0.54%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4CH1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  49721062 | PA      | $938137.00    | 0.06%             | 2031-11-25      | Variable      | 0.35%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H4SM3<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   8215224 | PA      | $238174.95    | 0.02%             | 2031-12-25      | Variable      | 0.57%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137H5DT1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  50485813 | PA      | $1310854.04   | 0.08%             | 2031-12-25      | Variable      | 0.50%                 | No            | 2                  | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137H9AD1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   2836463 | PA      | $2803887.43   | 0.18%             | 2052-09-25      | Floating      | 5.00%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HAAL0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  29100000 | PA      | $605082.12    | 0.04%             | 2033-05-25      | Variable      | 0.27%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HDJK7<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  25401461 | PA      | $358386.68    | 0.02%             | 2029-05-25      | Variable      | 0.41%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HFP33<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  28847080 | PA      | $820907.12    | 0.05%             | 2029-07-25      | Variable      | 0.82%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HHJ44<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7419164 | PA      | $514749.02    | 0.03%             | 2034-09-25      | Variable      | 0.91%                 | No            | 2                  | On Loan: No      |
| Freddie Mac                                      | Freddie Mac REMICS                                                                                                                     | CUSIP: 3137HJQL4<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   4169969 | PA      | $4192182.34   | 0.27%             | 2055-02-25      | Floating      | 5.13%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | FREMF 2025-K169 Mortgage Trust                                                                                                         | CUSIP: 3137HK2F0<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |  35704535 | PA      | $818512.18    | 0.05%             | 2035-01-25      | Variable      | 0.25%                 | No            | 2                  | On Loan: No      |
| FHLMC Multifamily Structured Pass Through Certs. | Freddie Mac Multifamily Structured Pass Through Certificates                                                                           | CUSIP: 3137HKSB1<br>LEI: S6XOOCT0IEG5ABCC6L87 | Long             | ABS-MBS          | USGSE             | US        |   7353849 | PA      | $163299.57    | 0.01%             | 2030-01-25      | Variable      | 0.57%                 | No            | 2                  | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38376RS56<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   1390732 | PA      | $1401262.46   | 0.09%             | 2067-01-20      | Floating      | 5.25%                 | No            | 2                  | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38381NMU9<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   3131653 | PA      | $3176779.31   | 0.20%             | 2055-06-20      | Floating      | 5.30%                 | No            | 2                  | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38383KU42<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   1464271 | PA      | $1464334.36   | 0.09%             | 2074-08-20      | Floating      | 4.83%                 | No            | 2                  | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38384XSB0<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   1835218 | PA      | $1836316.08   | 0.12%             | 2054-10-20      | Floating      | 5.23%                 | No            | 2                  | On Loan: No      |
| Government National Mortgage Association         | Government National Mortgage Association                                                                                               | CUSIP: 38385G5H8<br>LEI: 549300M8ZYFG0OCMTT87 | Long             | ABS-MBS          | USGA              | US        |   2861577 | PA      | $2841795.98   | 0.18%             | 2055-06-20      | Floating      | 5.37%                 | No            | 2                  | On Loan: No      |
| GREAT AMERICA LEASING RECEIVABLES                | GreatAmerica Leasing Receivables Funding LLC                                                                                           | CUSIP: 39154GAH9<br>LEI: 549300JFP7GIDD4UWO79 | Long             | ABS-O            | CORP              | US        |   2485000 | PA      | $2491945.33   | 0.16%             | 2027-10-15      | Fixed         | 4.52%                 | Yes           | 2                  | On Loan: No      |
| LAD Auto Receivables Trust                       | LAD Auto Receivables Trust 2024-3                                                                                                      | CUSIP: 505709AB1<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    620451 | PA      | $620806.03    | 0.04%             | 2027-11-15      | Fixed         | 4.64%                 | Yes           | 2                  | On Loan: No      |
| MFS Institutional Money Market Portfolio         | MFS Institutional Money Market Portfolio                                                                                               | CUSIP: 55291X109<br>LEI: 5L2W638H85N8T1136O07 | Long             | EC               | RF                | US        |  38990400 | NS      | $38998197.65  | 2.50%             |  |  |  | No            | 1                  | On Loan: No      |
| Michigan Finance Authority                       | MICHIGAN ST FIN AUTH REVENUE                                                                                                           | CUSIP: 59447TV83<br>LEI: 54930022O46HOX5J1D14 | Long             | DBT              | MUN               | US        |    446940 | PA      | $444327.83    | 0.03%             | 2061-07-25      | Fixed         | 1.30%                 | No            | 2                  | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L5                                                                                                 | CUSIP: 61691YAP6<br>LEI: 3IFG42XD94UUZ7FL2766 | Long             | ABS-MBS          | CORP              | US        |  10041965 | PA      | $445462.56    | 0.03%             | 2054-05-15      | Variable      | 1.26%                 | No            | 2                  | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L6                                                                                                 | CUSIP: 61692CBK3<br>LEI: 3IFG42XD94UUZ7FL2766 | Long             | ABS-MBS          | CORP              | US        |  11979818 | PA      | $461369.14    | 0.03%             | 2054-06-15      | Variable      | 1.14%                 | No            | 2                  | On Loan: No      |
| Morgan Stanley Capital I Trust                   | Morgan Stanley Capital I Trust 2021-L7                                                                                                 | CUSIP: 61772TBN3<br>LEI: 3IFG42XD94UUZ7FL2766 | Long             | ABS-MBS          | CORP              | US        |  27131047 | PA      | $1093980.80   | 0.07%             | 2054-10-15      | Variable      | 1.07%                 | No            | 2                  | On Loan: No      |
| Morgan Stanley Residential Mortgage Loan Trust   | Morgan Stanley Residential Mortgage Loan Trust 2025-NQM3                                                                               | CUSIP: 61778LAA3<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   1371650 | PA      | $1380846.60   | 0.09%             | 2070-05-25      | Variable      | 5.53%                 | Yes           | 2                  | On Loan: No      |
| Onslow Bay Financial LLC                         | OBX 2025-NQM8 Trust                                                                                                                    | CUSIP: 67449AAA3<br>LEI: 2549006UJL1L84XG2C80 | Long             | ABS-MBS          | CORP              | US        |   1034139 | PA      | $1041396.86   | 0.07%             | 2065-03-25      | Variable      | 5.47%                 | Yes           | 2                  | On Loan: No      |
| PFS Financing Corp.                              | PFS Financing Corp                                                                                                                     | CUSIP: 69335PFS9<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   3476000 | PA      | $3482149.74   | 0.22%             | 2029-01-15      | Floating      | 4.88%                 | Yes           | 2                  | On Loan: No      |
| PMT Loan Trust                                   | PMT Loan Trust 2025-INV10                                                                                                              | CUSIP: 69383EBK6<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   1715273 | PA      | $1715277.46   | 0.11%             | 2056-10-01      | Floating      | 5.58%                 | Yes           | 2                  | On Loan: No      |
| Palmer Square Loan Funding Ltd                   | Palmer Square Loan Funding 2025-2 Ltd                                                                                                  | CUSIP: 69704AAC5<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   5700000 | PA      | $5697150.00   | 0.36%             | 2033-07-15      | Floating      | 5.69%                 | Yes           | 2                  | On Loan: No      |
| Palmer Square Loan Funding Ltd                   | Palmer Square Loan Funding 2025-1 Ltd                                                                                                  | CUSIP: 69704CAC1<br>LEI: N/A                  | Long             | ABS-CBDO         | CORP              | KY        |   4300000 | PA      | $4258070.70   | 0.27%             | 2033-02-15      | Floating      | 5.41%                 | Yes           | 2                  | On Loan: No      |
| SBNA Auto Receivables Trust                      | SBNA Auto Receivables Trust 2025-SF1                                                                                                   | CUSIP: 78437XAB2<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |    460719 | PA      | $461114.44    | 0.03%             | 2031-03-17      | Fixed         | 5.12%                 | Yes           | 2                  | On Loan: No      |
| Santander Drive Auto Receivables Trust           | Santander Drive Auto Receivables Trust 2025-1                                                                                          | CUSIP: 80288DAB2<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1420511 | PA      | $1421028.59   | 0.09%             | 2027-08-16      | Fixed         | 4.76%                 | No            | 2                  | On Loan: No      |
| Santander Drive Auto Receivables Trust           | Santander Drive Auto Receivables Trust 2025-1                                                                                          | CUSIP: 80288DAC0<br>LEI: N/A                  | Long             | ABS-O            | CORP              | US        |   1200000 | PA      | $1203881.40   | 0.08%             | 2029-01-16      | Fixed         | 4.74%                 | No            | 2                  | On Loan: No      |
| Shackleton CLO LTD                               | Shackleton 2019-XIV Clo Ltd                                                                                                            | CUSIP: 81880XAY8<br>LEI: 549300HOHPZON6E4VH77 | Long             | ABS-CBDO         | CORP              | KY        |   3996016 | PA      | $3995936.08   | 0.26%             | 2034-07-20      | Floating      | 5.43%                 | Yes           | 2                  | On Loan: No      |
| 3650R Commercial Mortgage Trust                  | 3650R 2021-PF1 Commercial Mortgage Trust                                                                                               | CUSIP: 88581EAF8<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |  14408423 | PA      | $525417.55    | 0.03%             | 2054-11-15      | Variable      | 1.00%                 | No            | 2                  | On Loan: No      |
| TOLEDO HOSPITAL/THE                              | Toledo Hospital/The                                                                                                                    | CUSIP: 889184AF4<br>LEI: 5493009DCR7NWV6K4T34 | Long             | DBT              | CORP              | US        |   2421000 | PA      | $2474668.73   | 0.16%             | 2028-11-15      | Fixed         | 5.33%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810FD5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  68033121 | PA      | $71926133.35  | 4.60%             | 2028-04-15      | Fixed         | 3.63%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810QV3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 118763880 | PA      | $94794171.08  | 6.07%             | 2042-02-15      | Fixed         | 0.75%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810RA8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  37231063 | PA      | $28511930.50  | 1.83%             | 2043-02-15      | Fixed         | 0.63%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810RL4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  54650010 | PA      | $41188247.61  | 2.64%             | 2045-02-15      | Fixed         | 0.75%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810SB5<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  25419330 | PA      | $19258924.11  | 1.23%             | 2048-02-15      | Fixed         | 1.00%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810TE8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  42200820 | PA      | $23280398.86  | 1.49%             | 2052-02-15      | Fixed         | 0.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Bonds                                                                                                  | CUSIP: 912810TY4<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  37454505 | PA      | $34984932.10  | 2.24%             | 2054-02-15      | Fixed         | 2.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128282L3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  90123851 | PA      | $89255796.40  | 5.71%             | 2027-07-15      | Fixed         | 0.38%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128283R9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  57892988 | PA      | $57023169.33  | 3.65%             | 2028-01-15      | Fixed         | 0.50%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 9128285W6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 115209414 | PA      | $113939350.09 | 7.29%             | 2029-01-15      | Fixed         | 0.88%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828V49<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  13493143 | PA      | $13350508.75  | 0.85%             | 2027-01-15      | Fixed         | 0.38%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828Y38<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |   5163440 | PA      | $5120110.12   | 0.33%             | 2028-07-15      | Fixed         | 0.75%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828Z37<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  16372460 | PA      | $15597452.91  | 1.00%             | 2030-01-15      | Fixed         | 0.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 912828ZZ6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 181105068 | PA      | $171841498.12 | 11.00%            | 2030-07-15      | Fixed         | 0.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CBF7<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 202222085 | PA      | $189594367.35 | 12.14%            | 2031-01-15      | Fixed         | 0.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CDX6<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 104830616 | PA      | $96387025.53  | 6.17%             | 2032-01-15      | Fixed         | 0.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CEZ0<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  11709915 | PA      | $11068244.68  | 0.71%             | 2032-07-15      | Fixed         | 0.63%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CGK1<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  77072641 | PA      | $74598637.72  | 4.77%             | 2033-01-15      | Fixed         | 1.13%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CHP9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  69990363 | PA      | $68862032.17  | 4.41%             | 2033-07-15      | Fixed         | 1.38%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CJY8<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        | 115800353 | PA      | $116233861.64 | 7.44%             | 2034-01-15      | Fixed         | 1.75%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CLE9<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  29946850 | PA      | $30366670.40  | 1.94%             | 2034-07-15      | Fixed         | 1.88%                 | No            | 2                  | On Loan: No      |
| United States Treasury                           | U.S. Treasury Inflation-Indexed Notes                                                                                                  | CUSIP: 91282CNB3<br>LEI: 254900HROIFWPRGM1V77 | Long             | DBT              | UST               | US        |  57684698 | PA      | $58387339.53  | 3.74%             | 2030-04-15      | Fixed         | 1.63%                 | No            | 2                  | On Loan: No      |
| Wells Fargo Commercial Mortgage Trust            | Wells Fargo Commercial Mortgage Trust 2021-C60                                                                                         | CUSIP: 95003DBP2<br>LEI: N/A                  | Long             | ABS-MBS          | CORP              | US        |   9202671 | PA      | $567961.23    | 0.04%             | 2054-08-15      | Variable      | 1.49%                 | No            | 2                  | On Loan: No      |
| Morgan Stanley & Co. LLC                         | Long: SM11576   IRS USD R V 12MUSCPI SM11576_FLO INFLATIONZERO / Short: SM11576   IRS USD P F  2.48200 SM11576_FIX INFLATIONZERO       | CUSIP: 000000000<br>LEI: 9R7GPTSO7KV3UQJZQ078 | N/A              | DIR              |  | US        |  79900000 | OU      | $738341.52    | 0.05%             |  |  |  | No            | 2                  | On Loan: No      |
| LCH Ltd.                                         | Long: BM11591   IRS USD R V 12MUSCPI SM11591_FLO CCPINFLATIONZERO / Short: BM11591   IRS USD P F  2.63650 SM11591_FIX CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  40400000 | OU      | $199809.11    | 0.01%             |  |  |  | No            | 2                  | On Loan: No      |
| LCH Ltd.                                         | Long: BM11746   IRS USD R V 12MUSCPI SM11746_FLO CCPINFLATIONZERO / Short: BM11746   IRS USD P F  2.75500 SM11746_FIX CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  80400000 | OU      | $137680.18    | 0.01%             |  |  |  | No            | 2                  | On Loan: No      |
| LCH Ltd.                                         | Long: BM11926   IRS USD R V 12MUSCPI SM11926_FLO CCPINFLATIONZERO / Short: BM11926   IRS USD P F  2.74000 SM11926_FIX CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  84400000 | OU      | $-333125.11   | -0.02%            |  |  |  | No            | 2                  | On Loan: No      |
| LCH Ltd.                                         | Long: SM11925   IRS USD R F  3.17000 SM11925_FIX CCPINFLATIONZERO / Short: SM11925   IRS USD P V 12MUSCPI SM11925_FLO CCPINFLATIONZERO | CUSIP: 000000000<br>LEI: F226TOH6YD6XJB17KS62 | N/A              | DIR              |  | US        |  84400000 | OU      | $218547.89    | 0.01%             |  |  |  | No            | 2                  | On Loan: No      |
| Chicago Board of Trade                           | US 2YR NOTE (CBT) DEC25                                                                                                                | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       583 | NC      | $-14997.10    | -0.00%            |  |  |  | No            | 1                  | On Loan: No      |
| Chicago Board of Trade                           | US 5YR NOTE (CBT) DEC25                                                                                                                | CUSIP: 000000000<br>LEI: 549300EX04Q2QBFQTQ27 | N/A              | DIR              |  | US        |       196 | NC      | $-159204.33   | -0.01%            |  |  |  | No            | 1                  | On Loan: No      |
| POUND STERLING                                   | POUND STERLING                                                                                                                         | CUSIP: 000000000<br>LEI: N/A                  | Short            |  |  | GB        |        -2 | NS      | $-2.63        | -0.00%            |  |  |  | No            | N/A                | On Loan: No      |

### Signature

**Date Signed:** 2025-12-02

**Name of Applicant:** MFS SERIES TRUST IX

**Signature:** James Byrne

**Name of Signer:** James Byrne

**Title:** Assistant Treasurer