The fund invests primarily in high-quality municipal bonds issued by Massachusetts state and local governments, as well as by regional governmental and public financing authorities. Under normal circumstances, at least 80% of its assets will be invested in securities whose income is exempt from federal and Massachusetts state taxes. Although the fund has no limitations on the maturities of individual securities, its dollar-weighted average maturity is expected to be between 10 and 25 years. It is non-diversified.