Filed by MFS Municipal Income Trust
pursuant to Rule 425 under the Securities Act
of 1933
and deemed filed pursuant to Rule 14a-12
under the Securities Exchange Act of 1934
Subject Companies:
MFS High Income Municipal Trust
File No.: 811-05754
MFS High Yield Municipal Trust
File No.: 811-04992
MFS Investment Grade Municipal Trust
File No.: 811-05785
Date: March 12, 2026

| For Immediate Release |
Media Contacts: Dan Flaherty, +1 617.954.4256 |
| |
For Shareholders/Advisors: Brian Mastrullo, +1 617.954.7940 |
MFS MUNICIPAL CLOSED-END FUNDS ANNOUNCE
ADJOURNMENT OF
SPECIAL SHAREHOLDER MEETINGS
BOSTON (March 12, 2026) – MFS Investment Management
(“MFS”) announced today an adjournment of the special meeting of shareholders of MFS High Income Municipal Trust (NYSE:
CXE), MFS High Yield Municipal Trust (NYSE: CMU), MFS Investment Grade Municipal Trust (NYSE: CXH) (each a “Target Fund”
and collectively, the “Target Funds”), and MFS Municipal Income Trust (NYSE: MFM) (the “Surviving Fund”)
held on March 11, 2026 (each a “Meeting” and collectively, the “Meetings”).
Each Meeting is adjourned to April 2, 2026, at 11:00 a.m.
Eastern Time.
The Meetings were adjourned to allow for the solicitation
of additional shareholder votes relating to (i) a proposal that each Target Fund’s shareholders approve an Agreement and
Plan of Reorganization between each Target Fund and the Surviving Fund (each a “Reorganization” and collectively, the
“Reorganizations”) and (ii) a proposal that the Surviving Fund’s shareholders appoint of abrdn, Inc. (“Aberdeen”)
as the new investment adviser of the Surviving Fund, elect five new trustees of the Surviving Fund, and approve the issuance of
additional common shares of the Surviving Fund in connection with the Reorganizations. Each of these proposals is summarized below.
The Reorganizations
On December 10, 2025, the Board of Trustees (the “Board”)
of each Target Fund unanimously approved the Reorganizations. Shareholders of each Target Fund as of December 11, 2025, were mailed
a prospectus/proxy statement in early February 2026, providing additional information about each Reorganization and the factors
considered by each Target Fund’s Board in approving the relevant Target Fund’s Reorganization. Each Target Fund’s
Board determined that the Reorganization of that Target Fund into the Surviving Fund is in the best interests of the Target Fund’s
shareholders and recommends shareholders vote in favor of their Target Fund’s Reorganization.

Conditional Tender Offer for CMU and CXH
On March 4, 2026, MFS announced that the Board authorized
each of CMU and CXH to conduct separate conditional cash tender offers for up to 50% of outstanding common shares of CMU and CXH
at a price equal to 99% of CMU’s and CXH’s net asset value, respectively (each a “Tender Offer”). Each
Tender Offer will be subject to certain conditions that will be set forth in a tender offer statement on Schedule TO, which will
be filed with the U.S. Securities and Exchange Commission, and an offer to purchase, which will be mailed to shareholders of CMU
and CXH as of the record date upon commencement of the Tender Offer. Among other conditions, the commencement of each Tender Offer
is contingent upon CMU and CXH, as applicable, receiving the necessary shareholder vote in favor of its Reorganization. As such,
each Tender Offer will not commence unless and until the requisite shareholder vote is received at the adjourned special meeting
of shareholders for CMU and CXH, respectively, scheduled for April 2, 2026, or any further adjournment thereof.
Appointment of Aberdeen as Investment Adviser, the Election
of Five New Trustees, and Issuance of Additional Common Shares of the Surviving Fund
On December 10, 2025, the Board of the Surviving Fund unanimously
approved (i) a new investment management agreement with Aberdeen, the US Subsidiary of Aberdeen Investments, to serve as the investment
adviser to the Surviving Fund following the consummation of the Reorganizations, (ii) the nomination of five new trustees to serve
as the Surviving Fund’s board of trustees following the consummation of the Reorganizations, and (iii) the issuance of additional
common shares of the Surviving Fund to accommodate the Reorganizations. Shareholders of the Surviving Fund as of December 11, 2025,
were mailed a proxy statement in early February 2026, providing additional information and soliciting a vote in favor of each proposal,
all of which are recommended by the Surviving Fund’s Board.
Cautionary Statement Regarding Forward-Looking Statements
This press release may contain statements regarding plans
and expectations for the future that constitute forward-looking statements within The Private Securities Litigation Reform Act
of 1995. All statements other than statements of historical fact are forward-looking and can be identified by the use of words
such as “may,” “will,” “expect,” “anticipate,” “estimate,” “believe,”
“continue,” or other similar words. Such forward-looking statements are based on the fund’s current plans and expectations,
are not guarantees of future results or performance, and are subject to risks and uncertainties that could cause actual results
to differ materially from those described in the forward-looking statements. All forward-looking statements are as of the date
of this release only; the funds undertake no obligation to update or review any forward-looking statements. You are urged to carefully
consider all such factors.
About the Funds
The funds are closed-end investment company products advised
by MFS Investment Management. Closed-end funds, unlike open-end funds, are not continuously offered. There is a one-time public
offering and once issued, common shares of the funds are bought and sold in the open market through a stock exchange. Shares may
trade at a discount to the net asset value per share. Shares of the funds

are not FDIC-insured and are not deposits or other obligations
of, or guaranteed by, any bank. Shares of the funds involve investment risk, including possible loss of principal.
About MFS Investment Management
In 1924, MFS launched the first US open-end mutual fund, opening
the door to the markets for millions of everyday investors. Today, as a full-service global investment manager serving financial
advisors, intermediaries and institutional clients, MFS still serves a single purpose: to create long term value for clients by
allocating capital responsibly. That takes our powerful investment approach combining collective expertise, thoughtful risk management
and long-term discipline. Supported by our culture of shared values and collaboration, our teams of diverse thinkers actively debate
ideas and assess material risks to uncover what we believe are the best investment opportunities in the market. As of February
28, 2026, MFS had approximately US$669.8 billion in assets under management.
MFS Investment
Management
111 Huntington Ave., Boston, MA 02199
# # #