MFS (Massachusetts Financial Services Company, the fund's investment adviser) normally invests the fund’s assets primarily in municipal instruments. Municipal instruments are debt instruments issued by or for states, territories, or possessions of the United States or by their political subdivisions, agencies, authorities, or other government entities, to raise money for a variety of public and private purposes, including general financing for state and local governments, or financing for a specific project or public facility. Municipal instruments include general obligation bonds of municipalities, state or local governments, project or revenue-specific bonds, municipal lease obligations, and pre-refunded or escrowed bonds.

The fund invests, under normal market conditions, at least 80% of its net assets in securities and other investments, the interest on which is exempt from U.S. federal income tax and personal income tax, if any, of Maryland. However, interest from the fund’s investments may be subject to the U.S. federal alternative minimum tax. MFS may also invest the fund's assets in taxable instruments, including municipal instruments of other states.

MFS invests a significant percentage of the fund’s assets in municipal instruments of Maryland.

MFS may invest a significant percentage of the fund’s assets in a single issuer or a small number of issuers.

MFS may invest 25% or more of the fund’s assets in municipal instruments that finance similar types of projects, such as those relating to education, healthcare, housing, utilities, water or sewers. Municipal instruments whose interest is exempt from U.S. federal and state personal income tax include instruments issued by U.S. territories and possessions (such as Puerto Rico, Guam, and the U.S. Virgin Islands) and their political subdivisions and public corporations.

MFS primarily invests the fund’s assets in investment grade quality debt instruments, but may also invest the fund’s assets in below investment grade quality debt instruments.

While MFS may use derivatives for any investment purpose, to the extent MFS uses derivatives, MFS expects to use derivatives primarily to increase or decrease exposure to a particular market, segment of the market, or security, to increase or decrease interest rate exposure, or as alternatives to direct investments. Derivatives include futures, forward contracts, options, inverse floating rate instruments, and swaps.

MFS uses an active bottom-up investment approach to buying and selling investments for the fund. Investments are selected primarily based on fundamental analysis of individual instruments and their issuers. Quantitative screening tools that systematically evaluate instruments may also be considered. In structuring the fund, MFS also considers top-down factors.

For purposes of the fund's 80% policy, net assets include the amount of any borrowings for investment purposes.