Strategy. Under normal circumstances, the fund will invest at least 80% of its assets in, or derive at least 80% of its income from, securities that are exempt from regular federal income tax and that do not subject you to federal alternative minimum tax. The fund may also invest up to 20% of its assets in private activity bonds whose interest is generally subject to the federal alternative minimum tax. The fund invests primarily in debt securities rated AA- or better or Aa3 or better by Nationally Recognized Statistical Rating Organizations designated by the funds investment adviser, or unrated but determined by the funds investment adviser to be of equivalent quality. The fund may also invest in debt securities rated A- … Show more… Under normal circumstances, the fund will invest at least 80% of its assets in, or derive at least 80% of its income from, securities that are exempt from regular federal income tax and that do not subject you to federal alternative minimum tax. The fund may also invest up to 20% of its assets in private activity bonds whose interest is generally subject to the federal alternative minimum tax. The fund invests primarily in debt securities rated AA- or better or Aa3 or better by Nationally Recognized Statistical Rating Organizations designated by the funds investment adviser, or unrated but determined by the funds investment adviser to be of equivalent quality. The fund may also invest in debt securities rated A- or better or A3 or better by Nationally Recognized Statistical Rating Organizations designated by the funds investment adviser, or unrated but determined by the funds investment adviser to be of equivalent quality. The funds aggregate portfolio will have a dollar-weighted average effective maturity no greater than three years. The investment adviser uses a system of multiple portfolio managers in managing the funds assets. Under this approach, the portfolio of the fund is divided into segments managed by individual managers. The fund relies on the professional judgment of its investment adviser to make decisions about the funds portfolio investments. The basic investment philosophy of the investment adviser is to seek to invest in attractively priced securities that, in its opinion, represent good, long-term investment opportunities. Securities may be sold when the investment adviser believes that they no longer represent relatively attractive investment opportunities. Show less