Mfs High Yield Municipal Trust SC TO-I/A, filed May 11, 2026
Mfs High Yield Municipal Trust (CMU)
united states
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
SCHEDULE TO
TENDER OFFER STATEMENT UNDER SECTION 14(D)(1)
OR 13(E)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 3)
MFS
High Yield Municipal Trust
(Name of Subject Company (Issuer))
MFS High Yield
Municipal Trust
(Name of Filing Person (Issuer))
Common Shares,
Without Par
(Title of Class of Securities)
59318E102
(CUSIP Number of Class of Securities)
Christopher R.
Bohane
Massachusetts Financial Services Company
111 Huntington Avenue
Boston, MA 02199
Telephone: (617) 954-5000
(Name, address and telephone number of person authorized to receive notices and communications on behalf of filing persons)
With a Copy to:
David C. Sullivan
Ropes & Gray LLP
Prudential Tower
800 Boylston Street
Boston, MA 02199-3600
Telephone: (617) 951-7000
| o | Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer. |
| Check the appropriate boxes below to designate any transactions to which the statement relates: |
| o | third party tender offer subject to Rule 14d-1. | |
| x | issuer tender offer subject to Rule 13e-4. | |
| o | going-private transaction subject to Rule 13e-3. | |
| o | amendment to Schedule 13D under Rule 13d-2. |
Check the following box if the filing is a final amendment reporting the results of the tender offer. o
If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:
| o | Rule 13e-4(i) (Cross-Border Issuer Tender Offer) | |
| o | Rule 14d-1(d) (Cross-Border Third-Party Tender Offer) |
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explanatory note
This Amendment No. 3 (“Amendment No. 3”) amends and supplements the Schedule TO filed with the U.S, Securities and Exchange Commission (the “SEC”) on March 04, 2026, as amended April 06, 2026, and May 6, 2026, regarding the communications made for the commencement of a tender offer (the “Offer”) on April 6, 2026 by MFS High Yield Municipal Trust, a closed-end management investment company (the “Fund”), to purchase for cash up to 50% or 12,746,391 shares of the Fund’s outstanding common shares (the “Shares”) upon the terms and subject to the conditions of the Offer.
This Amendment No. 3 to Schedule TO is intended to satisfy the requirements pursuant to Rule 13e-4(c)(3) of the Exchange Act.
Forward-Looking Statements
This document contains 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 Fund undertakes no obligation to update or review any forward-looking statements. You are urged to carefully consider all such factors.
Items 1 through 11 and Item 13
The information set forth in the Offer to Purchase and the related Letter of Transmittal is incorporated herein by reference into this Amendment No. 3 in answer to Item 1 through Item 11 and Item 13 of Schedule TO.
Items 12. EXHIBITS
Item 12 of the Schedule TO is hereby amended and supplemented to add the following exhibits:
| Exhibit No. | Document |
| (a)(1)(i) | Offer to Purchase dated April 6, 2026.1 |
| (a)(1)(ii) | Letter of Transmittal.1 |
| (a)(1)(iii) | Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees.1 |
| (a)(1)(iv) | Letter to Clients.1 |
|
(a)(1)(v) |
|
| (a)(2) | None. |
| (a)(3) | Not Applicable. |
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| (a)(4) | Not Applicable. |
| (a)(5)(iii) | Press Release issued on April 6, 2026.1 |
| (a)(5)(iv) | Press Release issued on May 6, 2026.2 |
| (a)(5)(v) | Press Release issued on May 11, 2026.3 |
| (d) | None. |
| (g) | None. |
| (h) | None. |
| (s) | Filing Fee Table.3 |
| 1 | Previously filed on April 6, 2026, as an exhibit to the Schedule TO. | |
| 2 | Previously filed on May 6, 2026, as an exhibit to the Schedule TO. | |
| 3 | Filed herewith. |
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SIGNATURE
After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
| MFS High Yield Municipal Trust | |||
| By: | /s/ Christopher R. Bohane | ||
| Name: | Christopher R. Bohane | ||
| Title: | Assistant Secretary and Assistant Clerk | ||
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Exhibit (a)(5)(v)

| For Immediate Release | Media contact: Dan Flaherty, +1 617.954.4256 |
| For shareholders/advisors: Brian Mastrullo, +1 617.954.7940 |
MFS HIGH YIELD MUNICIPAL TRUST ANNOUNCES FINAL RESULTS OF TENDER OFFER
BOSTON (May 11, 2026) – MFS® High Yield Municipal Trust (the “Fund”) (NYSE: CMU) announced today that, in accordance with its tender offer for up to 50% of the Fund’s outstanding common shares (the “Shares”), which expired at 5:00 P.M., Eastern Time, on May 5, 2026, the Fund has accepted 12,746,391 Shares, representing 50% of Shares, for payment on or about May 11, 2026.
A total of 13,949,629.03 Shares were properly tendered and not withdrawn by May 5, 2026, the final date for withdrawals. Therefore, on a prorated basis, approximately 91.38% of the Shares so tendered by each shareholder have been accepted for payment. The purchase price of properly tendered Shares is 99% of the Fund’s net asset value (“NAV”) per Share calculated as of the close of regular trading on the New York Stock Exchange (“NYSE”) on May 5, 2026, which is equal to $3.75 per Share.
The Fund’s information agent for the tender offer is Georgeson LLC and the depositary agent for the tender offer is Computershare Trust Company, N.A. Any questions with regard to the tender offer may be directed to the information agent toll-free at 1-866-316-3922.
About the Fund
The Fund is a closed-end investment company product advised by MFS Investment Management. Closed-end funds, unlike open-end funds, are not continuously offered. Except pursuant to a tender offer, common shares of the Fund are only available for purchase/sale on the NYSE at the current market price. Shares may trade at a discount to NAV. Shares of the Fund are not FDIC-insured and are not deposits or other obligations of, or guaranteed by, any bank. Shares of the Fund involve investment risk, including possible loss of principal. For more complete information about the Fund, including risks, charges, and expenses, please see the Fund’s annual and semi-annual shareholder reports or contact your financial adviser.
About MFS Investment Management
In 1924, MFS launched the first U.S. 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 April 30, 2026, MFS manages $650.7 billion in assets on behalf of individual and institutional investors worldwide. Please visit mfs.com for more information.
MFS Investment Management 111 Huntington Ave., Boston, MA 02199
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