This fund allocates a minimum of 80% of its net assets, including any borrowed capital, to municipal securities. These investments are designed to provide income exempt from federal income tax, although they are not necessarily exempt from the federal alternative minimum tax (AMT). The fund's holdings include municipal bonds from issuers in Texas, as well as those in other U.S. states, territories, and possessions. It has the option to invest more than 25% of its total assets in bonds issued by Texas entities.