# EDGAR Filing Document

**Accession Number:** 0000783740
**File Stem:** 0000912938-23-000026
**Filing Date:** 2023-1
**Character Count:** 8024
**Document Hash:** 35abab8bb7357dd7f62aa732e7f56247
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000912938-23-000026.hdr.sgml**: 20230124

**ACCESSION NUMBER**: 0000912938-23-000026

**CONFORMED SUBMISSION TYPE**: 497

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20230124

**DATE AS OF CHANGE**: 20230124

**EFFECTIVENESS DATE**: 20230124

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MFS SERIES TRUST X
- **CENTRAL INDEX KEY:** 0000783740
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 1130

**FILING VALUES:**
- **FORM TYPE:** 497
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-01657
- **FILM NUMBER:** 23545944

**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 GOVERNMENT MORTGAGE FUND
- **DATE OF NAME CHANGE:** 19930408

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MFS GOVERNMENT INCOME PLUS FUND
- **DATE OF NAME CHANGE:** 19930312

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MASSACHUSETTS MFS GOVERNMENT INCOME PLUS FUND
- **DATE OF NAME CHANGE:** 19921015

## Series and Classes Contracts Data

### MFS Global Opportunistic Bond Fund (Series ID: S000028956)

---

|  |  |  |
|:---|:---|:---|
| Class Name | Ticker Symbol | Class ID   |
| A          | MGBAX         | C000088935 |
| B          | MGBBX         | C000088936 |
| C          | MGBDX         | C000088937 |
| I          | MGBJX         | C000088938 |
| R1         | MGBKX         | C000088939 |
| R2         | MGBLX         | C000088940 |
| R3         | MGBMX         | C000088941 |
| R4         | MGBNX         | C000088942 |
| R6         | MGBOX         | C000120923 |

---

## Series and Classes Contracts Data

### MFS Global Opportunistic Bond Fund (Series ID: S000028956)

| Class ID   | Class Name   | Ticker Symbol   |
|:---|:---|:---|
| C000088935 | A            | MGBAX           |
| C000088936 | B            | MGBBX           |
| C000088937 | C            | MGBDX           |
| C000088938 | I            | MGBJX           |
| C000088939 | R1           | MGBKX           |
| C000088940 | R2           | MGBLX           |
| C000088941 | R3           | MGBMX           |
| C000088942 | R4           | MGBNX           |
| C000120923 | R6           | MGBOX           |

![](image0.jpg)

SUPPLEMENT TO THE PROSPECTUS

*Supplement dated January 24, 2023, to the Prospectus dated March 30, 2022.*

## MFS<sup>®</sup> Global Opportunistic Bond Fund

(formerly MFS<sup>®</sup> Global Bond Fund)

------

#### Effective immediately, the sub-section entitled "Portfolio Manager(s)" under the main heading entitled "Summary of Key Information" is restated in its entirety as follows:

#### Portfolio Manager(s)

---

| | | |
|:---|:---|:---|
| **&nbsp;&nbsp;&nbsp;&nbsp;Portfolio Manager** | &nbsp;&nbsp;&nbsp; **Since** | &nbsp;&nbsp;&nbsp; **Title** |
| &nbsp;&nbsp; Pilar Gomez-Bravo | &nbsp;&nbsp;&nbsp; 2014 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Robert Spector | &nbsp;&nbsp;&nbsp; 2015 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Ward Brown | &nbsp;&nbsp;&nbsp; 2021 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Philipp Burgener | &nbsp;&nbsp;&nbsp; 2021 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; David Cole | &nbsp;&nbsp;&nbsp; 2021 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Andy Li | &nbsp;&nbsp;&nbsp; 2019 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; John Mitchell | &nbsp;&nbsp;&nbsp; January 20, 2023 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Matt Ryan | &nbsp;&nbsp;&nbsp; 2021 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Michael Skatrud | &nbsp;&nbsp;&nbsp; 2021 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |
| &nbsp;&nbsp; Erik Weisman | &nbsp;&nbsp;&nbsp; 2010 | &nbsp;&nbsp;&nbsp; Investment Officer of MFS |

---

#### Effective immediately, the sub-section entitled "Portfolio Manager(s)" under the main heading entitled "Management of the Fund" is restated in its entirety as follows:

#### Portfolio Manager(s)
Information regarding the portfolio manager(s) of the fund is set forth below. Further information regarding the portfolio manager(s), including other accounts managed, compensation, ownership of fund shares, and possible conflicts of interest, is available in the fund's SAI.

---

| | | |
|:---|:---|:---|
| **&nbsp;&nbsp;&nbsp;&nbsp;Portfolio Manager** | **&nbsp;&nbsp;&nbsp;&nbsp;Primary Role** | **&nbsp;&nbsp;&nbsp;&nbsp;Five Year History** |
| &nbsp;&nbsp; Pilar Gomez-Bravo | &nbsp;&nbsp; Co-Lead Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2013 |
| &nbsp;&nbsp; Robert Spector | &nbsp;&nbsp; Co-Lead Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2011 |
| &nbsp;&nbsp; Ward Brown | &nbsp;&nbsp; Emerging Markets Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2005 |
| &nbsp;&nbsp; Philipp Burgener | &nbsp;&nbsp; Structured Securities Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2003 |
| &nbsp;&nbsp; David Cole | &nbsp;&nbsp; Below Investment Grade Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2004 |
| &nbsp;&nbsp; Andy Li | &nbsp;&nbsp; Investment Grade Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2018; Portfolio Manager at Man GLG from 2014 to 2018 |
| &nbsp;&nbsp; John Mitchell | &nbsp;&nbsp; Investment Grade Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2003 |
| &nbsp;&nbsp; Matt Ryan | &nbsp;&nbsp; Emerging Markets Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 1997 |
| &nbsp;&nbsp; Michael Skatrud | &nbsp;&nbsp; Below Investment Grade Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2013 |
| &nbsp;&nbsp; Erik Weisman | &nbsp;&nbsp; Sovereign Debt Instruments Portfolio Manager | &nbsp;&nbsp; Employed in the investment area of MFS since 2002 |

---

1050290 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 1&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; GLB-SUP-I-012423