This fund primarily invests in municipal bonds, dedicating at least 80% of its net assets and any capital acquired through borrowing for investment purposes to these securities. The interest generated by these bonds is, according to bond counsel, exempt from both standard federal income taxes and the federal Alternative Minimum Tax. These municipal obligations are issued by or on behalf of U.S. states, territories, possessions, the District of Columbia, and their related authorities, agencies, instrumentalities, and political subdivisions. A small portion, up to 10% of its total assets, may also be allocated to similar unrated securities.