The Fund seeks to achieve its investment objective the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in a diversified portfolio of tax-exempt municipal bonds. Municipal bonds are obligations issued by or on behalf of states, territories and possessions of the United States (including the District of Columbia, Puerto Rico, the U.S. Virgin Islands, and Guam), their political subdivisions - such as cities and counties - and their agencies or authorities to finance public-purpose projects. All investments in the Fund are denominated in U.S. dollars. The interest on municipal bonds is excludable from gross income for federal income tax purposes, although a significant portion of such interest may be a tax-preference item for purposes of the federal alternative minimum tax (the AMT) applicable to noncorporate taxpayers.