Strategy. Under normal circumstances, the fund invests at least 80% of its assets in municipal securities. Municipal securities are securities and other investments with similar economic characteristics, the interest on which is exempt from regular federal income tax but which may be subject to the federal alternative minimum tax. The funds 80% policy may not be changed without a shareholder vote. Municipal securities include debt obligations issued by any of the 50 states and certain other municipal issuers and their political subdivisions, agencies and public authorities, certain other governmental issuers (such as Puerto Rico, the U.S. Virgin Islands and Guam) and other qualifying issuers. These securities include participation or other interests in municipal securities issued or backed by banks, insurance companies … Show more… Under normal circumstances, the fund invests at least 80% of its assets in municipal securities. Municipal securities are securities and other investments with similar economic characteristics, the interest on which is exempt from regular federal income tax but which may be subject to the federal alternative minimum tax. The funds 80% policy may not be changed without a shareholder vote. Municipal securities include debt obligations issued by any of the 50 states and certain other municipal issuers and their political subdivisions, agencies and public authorities, certain other governmental issuers (such as Puerto Rico, the U.S. Virgin Islands and Guam) and other qualifying issuers. These securities include participation or other interests in municipal securities issued or backed by banks, insurance companies and other financial institutions. Some municipal securities, such as general obligation issues, are backed by the issuers taxing authority, while other municipal securities, such as revenue issues, are backed only by revenues from certain facilities or other sources and not by the issuer itself. The fund may invest in securities of any maturity. The fund normally expects to maintain an average effective portfolio maturity of between three and ten years. The average effective portfolio maturity of the fund is a weighted average of all the maturities of the securities in the portfolio, computed by weighting each securitys effective maturity, as estimated by the subadviser, by the market value of the security, and any cash in the portfolio. For purposes of determining the funds average effective maturity, a securitys maturity date will generally be deemed to be the next interest rate reset date for an adjustable rate security or, if earlier, the date of the next demand feature, such as a put feature, when the fund would be entitled to receive payment of principal and interest. The subadviser may also take into account estimated future prepayments on securities, such as mortgage- backed securities, with uncertain future cash flows and estimations of call features and similar features and options. These estimates may prove to be incorrect. The fund focuses on investment grade bonds (that is, securities rated in the Baa/BBB categories or above or, if unrated or deemed to be unrated by the subadviser, determined to be of comparable credit quality by the subadviser), but may invest up to 20% of its assets in below investment grade bonds (that is, securities rated below the Baa/BBB categories or, if unrated or deemed to be unrated by the subadviser, determined to be of comparable credit quality by the subadviser) (commonly known as high yield or junk bonds). The fund may also invest in securities of other open-end or closed-end investment companies, including exchange-traded funds (ETFs), that invest primarily in municipal securities. Instead of, and/or in addition to, investing directly in particular securities, the fund may use instruments such as derivatives, including options, futures contracts and inverse floating rate instruments issued in tender option bond transactions, and other synthetic instruments that are intended to provide economic exposure to the securities or the issuer or to be used as a hedging technique. The fund may use one or more types of these instruments without limit, subject to applicable regulatory requirements. These instruments are taken into account when determining compliance with the funds 80% policy. For additional information regarding derivatives, see More on the funds investment strategies, investments and risksDerivatives in the Prospectus. The fund may also engage in a variety of transactions using derivatives in order to change the investment characteristics of its portfolio (such as shortening or lengthening duration) and for other purposes. The fund may leverage its assets by investing proceeds received through tender option bond transactions, which is considered a form of borrowing. See More on the funds investment strategies, investments and risksTender option bonds in the Prospectus. Show less