The investment seeks after-tax total return. The fund normally invests 80% assets in a diversified portfolio of municipal obligations that are exempt from regular federal income tax (?Municipal Securities?), direct obligations of the U.S. Treasury (?Treasury Securities?) and/or obligations of U.S. Government Agencies, instrumentalities and government-sponsored enterprises (?Agency Securities?). It may invest in securities of any maturity or duration, and may in the future alter its duration target range.