MFS Series Trust I
02/26/2026 | Press release | Distributed by Public on 02/26/2026 07:57
Prospectus by Investment Company (Form 497)
SUPPLEMENT TO THE STATEMENT OF ADDITIONAL INFORMATION
The date of this supplement is February 26, 2026.
For the MFS® Funds listed below:
|
MFS® BLENDED RESEARCH® EMERGING MARKETS EQUITY FUND |
MFS® MID CAP GROWTH FUND |
|
MFS® BLENDED RESEARCH® INTERNATIONAL EQUITY FUND |
MFS® NEW DISCOVERY FUND |
|
MFS® CORE EQUITY FUND |
MFS® RESEARCH INTERNATIONAL FUND |
|
MFS® GLOBAL NEW DISCOVERY FUND |
MFS® TECHNOLOGY FUND |
|
MFS® GLOBAL REAL ESTATE FUND |
MFS® U.S. GOVERNMENT CASH RESERVE FUND |
|
MFS® LOW VOLATILITY EQUITY FUND |
MFS® U.S. GOVERNMENT MONEY MARKET FUND |
|
MFS® LOW VOLATILITY GLOBAL EQUITY FUND |
MFS® VALUE FUND |
Effective immediately, the sub-sections entitled "Compensation," "Ownership of Fund Shares," and "Other Accounts" under the main heading entitled "APPENDIX D - PORTFOLIO MANAGER(S)" are hereby restated, with respect to MFS Blended Research Emerging Markets Equity Fund, MFS Blended Research International Equity Fund, MFS Low Volatility Equity Fund, and MFS Low Volatility Global Equity Fund only, as follows:
Compensation
MFS' philosophy is to align portfolio manager compensation with the goal to provide shareholders with long-term value through a collaborative investment process. Therefore, MFS uses long-term investment performance as well as contribution to the overall investment process and collaborative culture as key factors in determining portfolio manager compensation. In addition, MFS seeks to maintain total compensation programs that are competitive in the asset management industry in each geographic market where it has employees. MFS uses competitive compensation data to ensure that compensation practices are aligned with its goals of attracting, retaining, and motivating the highest-quality professionals.
MFS reviews portfolio manager compensation annually. In determining portfolio manager compensation, MFS uses quantitative means and qualitative means to help ensure a durable investment process. As of December 31, 2025, portfolio manager total cash compensation is a combination of base salary and performance bonus:
Base Salary - Base salary generally represents a smaller percentage of portfolio manager total cash compensation than performance bonus.
Performance Bonus - Generally, the performance bonus represents more than a majority of portfolio manager total cash compensation.
The performance bonus is based on a combination of quantitative and qualitative factors, generally with more weight given to the former and less weight given to the latter. The quantitative portion is primarily based on the pre-tax performance of accounts managed by the portfolio manager over a range of fixed-length time periods, intended to provide the ability to assess performance over time periods consistent with a full market cycle and a strategy's investment horizon. The fixed-length time periods include the portfolio manager's full tenure on each Fund/strategy and, when available, 10-, 5-, and 3-year periods. For portfolio managers who have served for less than three years, shorter-term periods, including the one-year period, will also be considered, as will performance in previous roles, if any, held at the firm. Emphasis is generally placed on longer performance periods when multiple performance periods are available. Performance is evaluated across the full set of strategies and portfolios managed by a given portfolio manager, relative to appropriate peer group universes and/or representative indices ("benchmarks"). As of December 31, 2025, the following benchmarks were used to measure the following portfolio managers' performance for the following Funds, and/or MFS Funds managed in a substantially similar strategy to the portion of the Fund managed by the portfolio managers, unless otherwise indicated:
DECEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Benchmark(s) |
|
MFS Blended Research Emerging Markets Equity Fund |
Jed Stocks |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds Morningstar Diversified Emerging Markets |
|
Nathan Bryant1 |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds |
|
|
Jim Fallon |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds |
|
|
Matt Krummell |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds |
|
|
Jonathan Sage |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds |
|
|
Jenney Zhang1 |
MSCI Emerging Markets Index (net div) Lipper Emerging Markets Funds |
|
|
MFS Blended Research International Equity Fund |
Jed Stocks |
MSCI All Country World (ex-US) Index (net div) Lipper International Large-Cap Core Funds Lipper International Multi-Cap Value Funds Lipper International Multi-Cap Core Funds Morningstar Foreign Large Blend |
|
Nathan Bryant1 |
MSCI All Country World (ex-US) Index (net div) Lipper International Multi-Cap Value Funds |
|
|
Jim Fallon |
MSCI All Country World (ex-US) Index (net div) Lipper International Multi-Cap Value Funds |
|
|
Matt Krummell |
MSCI All Country World (ex-US) Index (net div) Lipper International Multi-Cap Value Funds |
|
|
Jonathan Sage |
MSCI All Country World (ex-US) Index (net div) Lipper International Multi-Cap Value Funds |
|
|
Jenney Zhang1 |
MSCI All Country World (ex-US) Index (net div) Lipper International Multi-Cap Value Funds |
|
|
MFS Low Volatility Equity Fund |
Jim Fallon |
Standard & Poor's 500 Stock Index MSCI USA Minimum Volatility Index (net div) Lipper Large-Cap Core Funds Lipper Multi-Cap Core Funds Morningstar US Large Blend |
|
Nathan Bryant1 |
Standard & Poor's 500 Stock Index Lipper Multi-Cap Core Funds |
|
|
Matt Krummell |
Standard & Poor's 500 Stock Index Lipper Multi-Cap Core Funds |
|
|
Jonathan Sage |
Standard & Poor's 500 Stock Index Lipper Multi-Cap Core Funds |
|
|
Jed Stocks |
Standard & Poor's 500 Stock Index Lipper Multi-Cap Core Funds |
|
|
Jenney Zhang1 |
Standard & Poor's 500 Stock Index Lipper Multi-Cap Core Funds |
|
|
MFS Low Volatility Global Equity Fund |
Jim Fallon |
MSCI All Country World Index (net div) MSCI All Country World Minimum Volatility Index (net div) Lipper Global Large-Cap Core Funds Lipper Global Multi-Cap Core Funds Lipper Global Multi-Cap Value Funds Morningstar Global Large Stock Blend |
|
Nathan Bryant1 |
MSCI All Country World Index (net div) Lipper Global Multi-Cap Value Funds |
|
|
Matt Krummell |
MSCI All Country World Index (net div) Lipper Global Multi-Cap Value Funds |
|
|
Jonathan Sage |
MSCI All Country World Index (net div) Lipper Global Multi-Cap Value Funds |
|
|
Jed Stocks |
MSCI All Country World Index (net div) Lipper Global Multi-Cap Value Funds |
|
|
Jenney Zhang1 |
MSCI All Country World Index (net div) Lipper Global Multi-Cap Value Funds |
|
1 Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 1, 2026.
DECEMBER-SAI-COMBINED-SUP-I-022626
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Benchmarks may include versions and components of indices, custom indices, and linked indices that combine performance of different indices for different portions of the time period, where appropriate.
The qualitative portion is based on the results of an annual internal peer review process (where portfolio managers are evaluated by other portfolio managers, analysts, and traders) and management's assessment of overall portfolio manager contributions to the MFS investment process and the client experience (distinct from fund and other account performance).
The performance bonus may be in the form of cash and/or a deferred cash award, at the discretion of management. A deferred cash award is issued for a cash value and becomes payable over a three-year vesting period if the portfolio manager remains in the continuous employ of MFS or its affiliates. During the vesting period, the value of the unfunded deferred cash award will fluctuate as though the portfolio manager had invested the cash value of the award in an MFS fund(s) selected by the portfolio manager. A selected fund may, but is not required to, be a fund that is managed by the portfolio manager.
MFS Equity Plan - Portfolio managers also typically benefit from the opportunity to participate in the MFS Equity Plan. Equity interests are awarded by management, on a discretionary basis, taking into account tenure at MFS, contribution to the investment process, and other factors.
Finally, portfolio managers also participate in benefit plans (including a defined contribution plan and health and other insurance plans) and programs available generally to other employees of MFS. The percentage such benefits represent of any portfolio manager's compensation depends upon the length of the individual's tenure at MFS and salary level, as well as other factors.
Ownership of Fund Shares
The following table shows the dollar range of equity securities of the Fund beneficially owned by the Fund's portfolio manager(s) (including the value of any deferred cash award which is based on the performance of the Fund) as of the Fund's fiscal year ended August 31, 2025, unless otherwise indicated. The following dollar ranges apply:
N. None
A. $1 - $10,000
B. $10,001 - $50,000
C. $50,001 - $100,000
D. $100,001 - $500,000
E. $500,001 - $1,000,000
F. Over $1,000,000
|
Fund |
Portfolio Manager |
Dollar Range of Equity Securities in the Fund |
|
MFS Blended Research Emerging Markets Equity Fund |
Jed Stocks |
C |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Matt Krummell |
N |
|
|
Jonathan Sage |
B |
|
|
Jenney Zhang1 |
N |
|
|
MFS Blended Research International Equity Fund |
Jed Stocks |
C |
|
Nathan Bryant1 |
N |
|
|
Jim Fallon |
N |
|
|
Matt Krummell |
N |
|
|
Jonathan Sage |
N |
|
|
Jenney Zhang1 |
N |
|
DECEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Dollar Range of Equity Securities in the Fund |
|
MFS Low Volatility Equity Fund |
Jim Fallon |
D |
|
Nathan Bryant1 |
N |
|
|
Matt Krummell |
N |
|
|
Jonathan Sage |
N |
|
|
Jed Stocks |
N |
|
|
Jenney Zhang1 |
N |
|
|
MFS Low Volatility Global Equity Fund |
Jim Fallon |
D |
|
Nathan Bryant1 |
N |
|
|
Matt Krummell |
N |
|
|
Jonathan Sage |
D |
|
|
Jed Stocks |
B |
|
|
Jenney Zhang1 |
D |
|
1 Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 31, 2026.
Other Accounts
In addition to the Fund, each portfolio manager of the Fund is named as a portfolio manager of certain other accounts managed or sub-advised by MFS or an affiliate. Wholly-owned subsidiaries of registered investment companies are not considered separate accounts for purposes of number of accounts and total assets managed. The number and assets of these accounts were as follows as of the Fund's fiscal year ended August 31, 2025, unless otherwise indicated:
|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
MFS Blended Research Emerging Markets Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$9.5 billion |
|
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
34 |
$8.9 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
33 |
$9.3 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$12.5 billion |
||
|
Other Pooled Investment Vehicles |
16 |
$4.6 billion |
|||
|
Other Accounts |
36 |
$12.4 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
30 |
$8.8 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
DECEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
MFS Blended Research International Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$9.5 billion |
|
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
34 |
$8.9 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
33 |
$9.3 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$12.5 billion |
||
|
Other Pooled Investment Vehicles |
16 |
$4.6 billion |
|||
|
Other Accounts |
36 |
$12.4 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
30 |
$8.8 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
MFS Low Volatility Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$9.5 billion |
|
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
34 |
$8.9 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
33 |
$9.3 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$12.5 billion |
||
|
Other Pooled Investment Vehicles |
16 |
$4.6 billion |
|||
|
Other Accounts |
36 |
$12.4 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
30 |
$8.8 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
DECEMBER-SAI-COMBINED-SUP-I-022626
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|
Fund |
Portfolio Manager |
Category of Accounts Managed |
Number of Accounts |
Total Assets |
|
|
MFS Low Volatility Global Equity Fund |
Jed Stocks |
Registered Investment Companies2 |
15 |
$9.5 billion |
|
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
34 |
$8.9 billion |
|||
|
Jenney Zhang1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
Jim Fallon |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
33 |
$9.3 billion |
|||
|
Jonathan Sage |
Registered Investment Companies2 |
17 |
$12.5 billion |
||
|
Other Pooled Investment Vehicles |
16 |
$4.6 billion |
|||
|
Other Accounts |
36 |
$12.4 billion |
|||
|
Matt Krummell |
Registered Investment Companies2 |
14 |
$9.0 billion |
||
|
Other Pooled Investment Vehicles |
14 |
$3.2 billion |
|||
|
Other Accounts |
30 |
$8.8 billion |
|||
|
Nathan Bryant1 |
Registered Investment Companies2 |
16 |
$11.4 billion |
||
|
Other Pooled Investment Vehicles |
17 |
$4.3 billion |
|||
|
Other Accounts |
30 |
$10.5 billion |
|||
|
1 |
Became a portfolio manager of the Fund after the date referenced above; therefore, information is as of January 31, 2026. |
||||
|
2 |
Includes the Fund. |
||||
Advisory fees were not based upon performance of any of the accounts identified in the table above.
DECEMBER-SAI-COMBINED-SUP-I-022626
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MFS Series Trust I published this content on February 26, 2026, and is solely responsible for the information contained herein. Distributed via EDGAR on February 26, 2026 at 13:58 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]