MFS High Yield Municipal Trust (the Fund) is a diversified closed-end management investment company. The Fund's investment objective is to seek high current income exempt from federal income tax, but may also consider capital appreciation. The Fund invests, under normal market conditions, over 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 invests primarily in municipal instruments. The Fund invests in high-yield securities rated below investment grade. The Fund invests in various industries, including healthcare (hospitals), water and sewer utility, universities (colleges), tobacco, tax assessment and the United States treasury securities. The Fund offers a dividend reinvestment and cash purchase plan that allows common shareholders to reinvest all of the distributions paid by the fund. The Fund's investment advisor is Massachusetts Financial Services Company.