# EDGAR Filing Document

**Accession Number:** 0000798244
**File Stem:** 0001145549-23-015064
**Filing Date:** 2023-3
**Character Count:** 25651
**Document Hash:** 6eae1cb3e7b88aad295e09e40d4061aa
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001145549-23-015064.hdr.sgml**: 20230307

**ACCESSION NUMBER**: 0001145549-23-015064

**CONFORMED SUBMISSION TYPE**: N-MFP2

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20230228

**FILED AS OF DATE**: 20230307

**DATE AS OF CHANGE**: 20230307

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS SERIES TRUST I
- **CENTRAL INDEX KEY:** 0000798244
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1130

**FILING VALUES:**
- **FORM TYPE:** N-MFP2
- **SEC ACT:** 1940 Act
- **SEC FILE NUMBER:** 811-04777
- **FILM NUMBER:** 23711247

**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 I /MA/
- **DATE OF NAME CHANGE:** 19940427

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS LIFETIME MANAGED SECTORS FUND
- **DATE OF NAME CHANGE:** 19930408

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** LIFETIME MANAGED SECTORS TRUST
- **DATE OF NAME CHANGE:** 19920703

## Series and Classes Contracts Data

### MFS U.S. Government Cash Reserve Fund (Series ID: S000000762)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000002179 | A            | MSRXX           |
| C000002182 | B            | MCRXX           |
| C000002183 | C            | MCCXX           |
| C000002184 | R1           | CRVXX           |
| C000002186 | R2           | CRMXX           |
| C000002187 | R3           | CRJXX           |
| C000002188 | R4           | CRKXX           |
| C000206004 | R6           | CRRXX           |
| C000206005 | I            | CRHXX           |

# Form N-MFP: Monthly Schedule of Portfolio Holdings

## N-MFP: Filer Information

**Submission Type:** N-MFP2

**Live/Test Flag:** —

**Is Electronic Copy of Paper Format:** —

**CIK:** —

### General Information

**Report for (YYYY-MM-DD):** 2023-02-28

**EDGAR Series Identifier:** S000000762

**Total number of share classes in the series:** —

**Is this the fund's final filing on Form N-MFP?:** —

**Is Fund Liquidating?:** —

**Is Fund Merging/Being Acquired?:** —

**Has the fund acquired or merged with another fund during the reporting period?:** —

## Part A: Series-Level Information about the Fund

### Service Providers
| Item   | Role                          | Details                                            | File/CIK Number   |
|:---|:---|:---|:---|
| A.5    | Administrator                 | Massachusetts Financial Services Company           |  |
| A.4    | Independent Public Accountant | Deloitte & Touche LLP<br>City: Boston<br>State: MA |  |
| A.6    | Transfer Agent                | MFS Service Center, Inc<br>CIK: 0000769188         | 084-01316         |

### Fund Characteristics & Assets

- **A.1 - Securities Act File Number:** 033-07638

- **A.7 - Is this a Feeder Fund?:** No

- **A.8 - Is this a Master Fund?:** No

- **A.9 - Is this series primarily used to fund insurance company separate accounts?:** No

- **A.10 - Money Market Fund Category:** Exempt Government

- **A.11 - WAM:** 9 days

- **A.12 - WAL:** 9 days

- **Total Value of Portfolio Securities:** $477532598.75

- **Amortized Cost of Portfolio Securities:** $477530097.22

- **Cash:** $502.35

- **Total Other Assets:** $77584.79

- **Total Liabilities:** $1686953.02

- **Net Assets of Series:** $475921231.34

- **Number of Shares Outstanding (Series):** 476156039.37

- **Stable Price Per Share:** $1.00

- **7-Day Gross Yield:** 4.5300%

### Weekly Liquid Assets
| Period         | Daily Liquid Assets ($)   | Weekly Liquid Assets ($)   | Daily Liquid Assets (%)   | Weekly Liquid Assets (%)   |
|:---|:---|:---|:---|:---|
| Friday, Week 1 |  | $490290950.79              |  | 99.9700%                   |
| Friday, Week 2 |  | $483374241.31              |  | 99.9600%                   |
| Friday, Week 3 |  | $479949334.31              |  | 99.9800%                   |
| Friday, Week 4 |  | $478447648.97              |  | 99.9800%                   |
| Friday, Week 5 |  | $0.00                      |  | 0.0000%                    |

## Part B: Class-Level Information about the Fund

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1000.00

- **B.3 - Net Assets of Class:** $171916752.59

- **B.4 - Shares Outstanding:** 172001585.10

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class A during the period, MFS waived: $1,773 management fees; $19,511 expense limitation; MFD waived: $33,664 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $1473872.15               | $5365072.82             |
| Week 2   | $140252.87                | $4634932.31             |
| Week 3   | $244785.57                | $3180329.51             |
| Week 4   | $1255542.93               | $2071220.16             |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $3221599.98

- **Gross Redemptions for month:** $14258394.17

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1000.00

- **B.3 - Net Assets of Class:** $4275372.43

- **B.4 - Shares Outstanding:** 4277478.73

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class B during the period, MFS waived: $44 management fees; $484 expense limitation; MFD waived: $3,351 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $14471.49                 | $14373.18               |
| Week 2   | $0.00                     | $43560.43               |
| Week 3   | $25.22                    | $3172.02                |
| Week 4   | $3592.77                  | $113861.00              |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $18089.48

- **Gross Redemptions for month:** $162469.28

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1000.00

- **B.3 - Net Assets of Class:** $25755266.16

- **B.4 - Shares Outstanding:** 25767956.16

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class C during the period, MFS waived: $269 management fees; $2,990 expense limitation; MFD waived: $20,381 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $128539.26                | $1280742.79             |
| Week 2   | $38187.00                 | $688427.20              |
| Week 3   | $66900.46                 | $429948.76              |
| Week 4   | $43485.67                 | $631092.48              |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $245692.57

- **Gross Redemptions for month:** $2881232.83

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $8990303.39

- **B.4 - Shares Outstanding:** 8994729.31

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class R1 during the period, MFS waived: $91 management fees; $1,003 expense limitation; MFD waived: $6,954 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $39929.29                 | $65431.44               |
| Week 2   | $60741.58                 | $52.01                  |
| Week 3   | $22212.17                 | $201467.55              |
| Week 4   | $9384.22                  | $22634.07               |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $131153.06

- **Gross Redemptions for month:** $225902.08

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $19119731.55

- **B.4 - Shares Outstanding:** 19129321.71

- **B.7.7 - 7-Day Net Yield:** 4.0800%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class R2 during the period, MFS waived: $196 management fees; $2,154 expense limitation; MFD waived: $7,467 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $99714.59                 | $86591.87               |
| Week 2   | $14205.13                 | $822578.86              |
| Week 3   | $483980.95                | $27238.66               |
| Week 4   | $235623.75                | $196173.35              |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $876071.66

- **Gross Redemptions for month:** $1472482.11

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $17908549.75

- **B.4 - Shares Outstanding:** 17917371.05

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class R3 during the period, MFS waived: $180 management fees; $1,974 expense limitation; MFD waived: $3,420 12b-1 fees.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $155147.63                | $112489.18              |
| Week 2   | $22801.70                 | $4587.70                |
| Week 3   | $270212.43                | $176143.32              |
| Week 4   | $42182.83                 | $3326.74                |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $489464.96

- **Gross Redemptions for month:** $296560.67

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $2717239.61

- **B.4 - Shares Outstanding:** 2718578.24

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class R4 during the period, MFS waived: $27 management fees; $301 expense limitation.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $8674.05                  | $0.00                   |
| Week 4   | $0.00                     | $47.05                  |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $8627.00

- **Gross Redemptions for month:** $0.00

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $208575253.39

- **B.4 - Shares Outstanding:** 208678044.13

- **B.7.7 - 7-Day Net Yield:** 4.1600%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class R6 during the period, MFS waived: $2,109 management fee; $23,138 expense limitation.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $690533.98                | $491811.92              |
| Week 2   | $3215.72                  | $467891.46              |
| Week 3   | $176136.99                | $521722.64              |
| Week 4   | $54734.30                 | $247149.00              |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $970653.58

- **Gross Redemptions for month:** $1602182.26

### Class: Unknown Class (—)

- **B.2 - Minimum Initial Investment:** $1.00

- **B.3 - Net Assets of Class:** $16662762.47

- **B.4 - Shares Outstanding:** 16670974.93

- **B.7.7 - 7-Day Net Yield:** 4.1000%

- **Person Paying for Fund Expenses?:** Yes

- **Expense Reimbursement/Waiver Description:** For Class I during the period, MFS waived: $169 management fees; $1,851 expense limitation.

**Weekly Flows:**

| Period   | Gross Subscriptions ($)   | Gross Redemptions ($)   |
|:---|:---|:---|
| Week 1   | $660769.49                | $201375.61              |
| Week 2   | $4172.50                  | $74894.19               |
| Week 3   | $40.00                    | $80735.33               |
| Week 4   | $2831.13                  | $502.77                 |

**Monthly Shareholder Flow Activity:**

- **Gross Subscriptions for month:** $667813.12

- **Gross Redemptions for month:** $364960.90

## Part C: Schedule of Portfolio Securities

### Security 1: BOFA Securities

- **C.1 - Title:** Bank of America NA 4.510000%
- **C.6 - Investment Category:** U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash
- **Identifiers:** C.3 - CUSIP: 03199T002, C.3 - LEI: 549300HN4UKV1E2R3U73, CIK: 0001102113, C.5 - Other ID: 03199T002_4.51_0301
- **C.18 - Value (incl. sponsor support):** $43767000.00
- **C.18.a - Value (excl. sponsor support):** $43767000.00
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 9.2000%
- **C.17 - Yield as of Reporting Date:** 4.5100%
- **C.11 - Maturity Date (WAM):** 2023-03-01
- **C.12 - Maturity Date (WAL):** 2023-03-01
- **C.13 - Final Legal Maturity Date:** 2023-03-01
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 2: Federal Farm Credit Bank

- **C.1 - Title:** Federal Farm Credit Bank
- **C.6 - Investment Category:** U.S. Government Agency Debt
- **Identifiers:** C.3 - CUSIP: 313312CM0, C.4 - ISIN: US313312CM02
- **C.18 - Value (incl. sponsor support):** $30500000.00
- **C.18.a - Value (excl. sponsor support):** $30500000.00
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 6.4100%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2023-03-01
- **C.12 - Maturity Date (WAL):** 2023-03-01
- **C.13 - Final Legal Maturity Date:** 2023-03-01
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 3: Federal Home Loan Bank

- **C.1 - Title:** Federal Home Loan Bank
- **C.6 - Investment Category:** U.S. Government Agency Debt
- **Identifiers:** C.3 - CUSIP: 313384CM9, C.4 - ISIN: US313384CM96, C.3 - LEI: 2549001DPIFGXC1TOL40
- **C.18 - Value (incl. sponsor support):** $34000000.00
- **C.18.a - Value (excl. sponsor support):** $34000000.00
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 7.1400%
- **C.17 - Yield as of Reporting Date:** 0.0000%
- **C.11 - Maturity Date (WAM):** 2023-03-01
- **C.12 - Maturity Date (WAL):** 2023-03-01
- **C.13 - Final Legal Maturity Date:** 2023-03-01
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 4: Federal Home Loan Mortgage Corp.

- **C.1 - Title:** Federal Home Loan Mortgage Corp.
- **C.6 - Investment Category:** U.S. Government Agency Debt
- **Identifiers:** C.3 - CUSIP: 313396CS0, C.4 - ISIN: US313396CS05, C.3 - LEI: S6XOOCT0IEG5ABCC6L87
- **C.18 - Value (incl. sponsor support):** $33979188.94
- **C.18.a - Value (excl. sponsor support):** $33979188.94
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 7.1400%
- **C.17 - Yield as of Reporting Date:** 3.6000%
- **C.11 - Maturity Date (WAM):** 2023-03-06
- **C.12 - Maturity Date (WAL):** 2023-03-06
- **C.13 - Final Legal Maturity Date:** 2023-03-06
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? No, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 5: Federal National Mortgage Assoc.

- **C.1 - Title:** Federal National Mortgage Assoc.
- **C.6 - Investment Category:** U.S. Government Agency Debt
- **Identifiers:** C.3 - CUSIP: 313588CT0, C.4 - ISIN: US313588CT02, C.3 - LEI: B1V7KEBTPIMZEU4LTD58
- **C.18 - Value (incl. sponsor support):** $33975028.36
- **C.18.a - Value (excl. sponsor support):** $33975028.36
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 7.1400%
- **C.17 - Yield as of Reporting Date:** 3.7400%
- **C.11 - Maturity Date (WAM):** 2023-03-07
- **C.12 - Maturity Date (WAL):** 2023-03-07
- **C.13 - Final Legal Maturity Date:** 2023-03-07
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? No, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 6: JP Morgan Securities LLC

- **C.1 - Title:** JP Morgan Securities LLC 4.510000%
- **C.6 - Investment Category:** U.S. Treasury Repurchase Agreement, if collateralized only by U.S. Treasuries (including Strips) and cash
- **Identifiers:** C.3 - CUSIP: 446199002, C.3 - LEI: ZBUT11V806EZRVTWT807, CIK: 0001168163, C.5 - Other ID: 446199002_4.51_0301
- **C.18 - Value (incl. sponsor support):** $43861000.00
- **C.18.a - Value (excl. sponsor support):** $43861000.00
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 9.2200%
- **C.17 - Yield as of Reporting Date:** 4.5100%
- **C.11 - Maturity Date (WAM):** 2023-03-01
- **C.12 - Maturity Date (WAL):** 2023-03-01
- **C.13 - Final Legal Maturity Date:** 2023-03-01
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 7: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796U31, C.4 - ISIN: US912796U310, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $25931558.64
- **C.18.a - Value (excl. sponsor support):** $25931558.64
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 5.4500%
- **C.17 - Yield as of Reporting Date:** 4.2800%
- **C.11 - Maturity Date (WAM):** 2023-03-23
- **C.12 - Maturity Date (WAL):** 2023-03-23
- **C.13 - Final Legal Maturity Date:** 2023-03-23
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 8: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796Y86, C.4 - ISIN: US912796Y866, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $18736276.13
- **C.18.a - Value (excl. sponsor support):** $18736276.13
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 3.9400%
- **C.17 - Yield as of Reporting Date:** 3.8600%
- **C.11 - Maturity Date (WAM):** 2023-03-07
- **C.12 - Maturity Date (WAL):** 2023-03-07
- **C.13 - Final Legal Maturity Date:** 2023-03-07
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 9: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796YB9, C.4 - ISIN: US912796YB94, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $49161052.27
- **C.18.a - Value (excl. sponsor support):** $49161052.27
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 10.3300%
- **C.17 - Yield as of Reporting Date:** 2.2100%
- **C.11 - Maturity Date (WAM):** 2023-03-02
- **C.12 - Maturity Date (WAL):** 2023-03-02
- **C.13 - Final Legal Maturity Date:** 2023-03-02
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 10: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796YK9, C.4 - ISIN: US912796YK93, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $18731322.92
- **C.18.a - Value (excl. sponsor support):** $18731322.92
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 3.9400%
- **C.17 - Yield as of Reporting Date:** 4.0000%
- **C.11 - Maturity Date (WAM):** 2023-03-09
- **C.12 - Maturity Date (WAL):** 2023-03-09
- **C.13 - Final Legal Maturity Date:** 2023-03-09
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 11: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796YL7, C.4 - ISIN: US912796YL76, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $36931010.54
- **C.18.a - Value (excl. sponsor support):** $36931010.54
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 7.7600%
- **C.17 - Yield as of Reporting Date:** 4.2000%
- **C.11 - Maturity Date (WAM):** 2023-03-16
- **C.12 - Maturity Date (WAL):** 2023-03-16
- **C.13 - Final Legal Maturity Date:** 2023-03-16
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 12: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796Z69, C.4 - ISIN: US912796Z699, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $34444233.51
- **C.18.a - Value (excl. sponsor support):** $34444233.51
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 7.2400%
- **C.17 - Yield as of Reporting Date:** 4.1700%
- **C.11 - Maturity Date (WAM):** 2023-03-14
- **C.12 - Maturity Date (WAL):** 2023-03-14
- **C.13 - Final Legal Maturity Date:** 2023-03-14
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 13: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796Z77, C.4 - ISIN: US912796Z772, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $31920177.92
- **C.18.a - Value (excl. sponsor support):** $31920177.92
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 6.7100%
- **C.17 - Yield as of Reporting Date:** 4.3100%
- **C.11 - Maturity Date (WAM):** 2023-03-21
- **C.12 - Maturity Date (WAL):** 2023-03-21
- **C.13 - Final Legal Maturity Date:** 2023-03-21
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

### Security 14: U.S. Treasury Bill

- **C.1 - Title:** U.S. Treasury Bill
- **C.6 - Investment Category:** U.S. Treasury Debt
- **Identifiers:** C.3 - CUSIP: 912796Z85, C.4 - ISIN: US912796Z855, C.3 - LEI: 254900HROIFWPRGM1V77
- **C.18 - Value (incl. sponsor support):** $41594749.52
- **C.18.a - Value (excl. sponsor support):** $41594749.52
- **Principal Amount:** —
- **Amortized Cost:** —
- **Fair Value:** —
- **C.19 - Percentage of Net Assets:** 8.7400%
- **C.17 - Yield as of Reporting Date:** 4.4000%
- **C.11 - Maturity Date (WAM):** 2023-03-28
- **C.12 - Maturity Date (WAL):** 2023-03-28
- **C.13 - Final Legal Maturity Date:** 2023-03-28
- **Characteristics:** C.14 Has Demand Feature? No, C.15 Has Guarantee? No, C.16 Has Enhancement? No, C.22 Is an Illiquid Security? No, C.20 Is a Daily Liquid Asset? Yes, C.21 Is a Weekly Liquid Asset? Yes, C.23 Categorized at Level 3? No

## N-MFP: Signatures

**Registrant:** MFS Series Trust I

**Date:** 2023-03-07

**By:** Kino Clark

**Name of Signing Officer:** Kino Clark

**Title of Signing Officer:** Assistant Treasurer