The investment seeks total return, consisting of current income exempt from federal income tax and of capital appreciation, consistent with moderate fluctuation of principal. Under normal circumstances, the fund invests at least 80% of its total net assets (including the amount of any borrowings for investment purposes) in bonds that pay interest exempt from federal income tax (including the federal alternative minimum tax). It invests at least 65% of its total assets in tax-exempt bonds that, at the time of purchase, are rated investment grade or are unrated but determined to be of comparable quality. The fund may invest in bonds of any maturity.