MFS High Income Municipal Trust (the Fund) is a closed-end management investment company. The fund's investment objective is to seek high income exempt from federal income tax, but may also consider capital appreciation. The fund invests, under normal market conditions, at least 80% of its net assets, including assets attributable to preferred shares and borrowings for investment purposes, in tax-exempt bonds and tax-exempt notes. The fund may invest 25% or more of the fund's total assets in municipal instruments that finance similar projects, such as those relating to education, healthcare, housing, utilities, water, or sewers. The fund may invest up to 100% of the fund's assets in less than investment grade quality debt instruments (lower quality debt instruments). The fund may invest a relatively large percentage of the fund's assets in a single issuer or a small number of issuers. The investment adviser for the Fund is Massachusetts Financial Services Company.