SEC Form N-CSRS filed by MFS High Income Municipal Trust

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-05754

MFS HIGH INCOME MUNICIPAL TRUST

(Exact name of registrant as specified in charter)

111 Huntington Avenue, Boston, Massachusetts 02199 (Address of principal executive offices) (Zip code)

Christopher R. Bohane

Massachusetts Financial Services Company

111Huntington Avenue Boston, Massachusetts 02199

(Name and address of agents for service)

Registrant’s telephone number, including area code: (617) 954-5000

Date of fiscal year end: November 30

Date of reporting period: May 31, 2025

ITEM 1. REPORTS TO STOCKHOLDERS.

Item 1(a):

Item 1(b):

A copy of the notice transmitted to the Registrant’s shareholders in reliance on Rule 30e-3 of the Investment Company Act of 1940, as amended that contains disclosure specified by paragraph (c)(3) of Rule 30e-3 is attached hereto as EX-99.30e-3Notice.

ITEM 2. CODE OF ETHICS.

During the period covered by this report, the Registrant has not amended any provision in its Code of Ethics (the “Code”) that relates to an element of the Code’s definition enumerated in paragraph (b) of Item 2 of this Form N-CSR. During the period covered by this report, the Registrant did not grant a waiver, including an implicit waiver, from any provision of the Code.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable for semi-annual reports.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable for semi-annual reports.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable for semi-annual reports.

ITEM 6. INVESTMENTS

A schedule of investments of the Registrant is included as part of the report to shareholders of the Registrant under Item 1(a) of this Form N-CSR.

ITEM 7. FINANCIAL STATEMENTS AND FINANCIAL HIGHLIGHTS FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 8. CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 9. PROXY DISCLOSURES FOR OPEN-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 10. RENUMERATION PAID TO DIRECTORS, OFFICERS, AND OTHERS OF OPEN-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 11. STATEMENT REGARDING BASIS FOR APPROVAL OF INVESTMENT ADVISORY CONTRACT.

Not applicable.

ITEM 12. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable for semi-annual reports.

ITEM 13. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Portfolio Manager(s)

Information regarding the portfolio manager(s) of the MFS High Income Municipal Trust (the "Fund"), is set forth below. Each portfolio manager is primarily responsible for the day-to-day management of the Fund.

Geoffrey Schechter has announced his intention to retire effective September 30, 2025, and he will no longer be a portfolio manager of the Fund as of that date.

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, 2023, 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, 2023, the following benchmarks were used to measure the following portfolio manager's performance for the Fund:

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) as of the Fund's fiscal year ended November 30, 2024. 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

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. The number and assets of these accounts were as follows as of the Fund's fiscal year ended November 30, 2024:

Advisory fees are not based upon performance of any of the accounts identified in the table above.

Potential Conflicts of Interest

MFS seeks to identify potential conflicts of interest resulting from a portfolio manager’s management of both the Fund and other accounts, and has adopted policies and procedures reasonably designed to address such potential conflicts. There is no guarantee that MFS will be successful in identifying or mitigating conflicts of interest.

The management of multiple funds and accounts (including accounts in which MFS, an affiliate, an employee, an officer, or a director has an interest) gives rise to conflicts of interest if the funds and accounts have different objectives and strategies, benchmarks, time horizons, and fees, as a portfolio manager must allocate his or her time and investment ideas across multiple funds and accounts. In certain instances, there are securities which are suitable for the Fund’s portfolio as well as for one or more other accounts advised by MFS or its subsidiaries (including accounts in which MFS, an affiliate, an employee, an officer, or a director has an interest). MFS' trade allocation policies could have a detrimental effect on the Fund if the Fund’s orders do not get fully executed or are delayed in getting executed due to being aggregated with those of other accounts advised by MFS or its subsidiaries. A portfolio manager may execute transactions for another fund or account that may adversely affect the value of the Fund’s investments. Investments selected for funds or accounts other than the Fund may outperform investments selected for the Fund.

When two or more accounts are simultaneously engaged in the purchase or sale of the same security, the securities are allocated among clients in a manner believed by MFS to be fair and equitable to each over time. Allocations may be based on many factors and may not always be pro rata based on assets managed. The allocation methodology could have a detrimental effect on the price or availability of a security with respect to the Fund.

MFS and/or a portfolio manager may have a financial incentive to allocate favorable or limited opportunity investments or structure the timing of investments to favor accounts other than the Fund; for instance, those that pay a higher advisory fee and/or have a performance adjustment, those that include an investment by the portfolio manager, and/or those in which MFS, its affiliates, its employees, its officers, and/or its directors own or have an interest.

To the extent permitted by applicable law, certain accounts may invest their assets in other accounts advised by MFS or its affiliates, including accounts that are advised by one or more of the same portfolio manager(s), which could result in conflicts of interest relating to asset allocation, timing of purchases and redemptions, and increased profitability for MFS, its affiliates, and/or its personnel, including portfolio managers.