Under normal circumstances, the fund invests at least 80% of its net assets in municipal obligations that are exempt from federal income tax (including securities subject to the federal alternative minimum tax ("AMT")). It invests at least 50% of its assets in municipal bonds rated BBB or lower by S&P Global Ratings or Baa or lower by Moody's Investors Service, Inc., at the time of investment, or the equivalent by another independent rating agency or the unrated equivalent as determined by the Adviser.