Strategy. Under normal market conditions, the fund invests at least 80% of its net assets (including, for this purpose, any borrowings for investment purposes) in municipal securities that pay interest not subject to regular federal income tax. Some of these investments in municipal securities may pay interest that is not exempt from the federal alternative minimum tax (AMT). Municipal securities may include debt obligations of U.S. states, territories, counties, cities, political subdivisions, government agencies and instrumentalities. The fund also invests in non-governmental municipal issuers, including, but not limited to, healthcare organizations, corporate issuers of municipal debt, and various project finance bond issues. The fund primarily invests in general obligation and revenue obligation securities, including fixed and variable rate securities, municipal notes … Show more… Under normal market conditions, the fund invests at least 80% of its net assets (including, for this purpose, any borrowings for investment purposes) in municipal securities that pay interest not subject to regular federal income tax. Some of these investments in municipal securities may pay interest that is not exempt from the federal alternative minimum tax (AMT). Municipal securities may include debt obligations of U.S. states, territories, counties, cities, political subdivisions, government agencies and instrumentalities. The fund also invests in non-governmental municipal issuers, including, but not limited to, healthcare organizations, corporate issuers of municipal debt, and various project finance bond issues. The fund primarily invests in general obligation and revenue obligation securities, including fixed and variable rate securities, municipal notes and private placements, auction-rate securities, variable rate demand notes, lease-backed obligations and certificates of participation. The fund may from time to time invest temporarily up to 20% of its net assets in taxable securities of at least comparable quality to the municipal securities in which the Fund invests. The fund may also invest up to 25% of its net assets in municipal securities that are subject to the AMT. The fund has no policy limiting its investments in municipal securities whose issuers are located in the same state or territory. However, the fund currently intends to invest no more than 25% of the funds net assets in issuers located in the same state. The fund may hold up to 15% of its net assets in illiquid or thinly traded securities, which may include securities that are subject to resale restrictions such as those issued pursuant to Rule 144A of the Securities Act of 1933, as amended. The fund may invest in securities that do not produce immediate cash income, such as zero coupon securities and securities that are in payment default. The fund invests at least 80% of its net assets in investment grade municipal securities, as determined by a nationally recognized rating organization (NRSRO) (e.g., Baa3 or higher by Moodys Investors Service, Inc. (Moodys)) or if unrated, determined to be of comparable quality by the investment adviser. The fund may also invest in municipal securities that are less-than-investment grade, as determined by an NRSRO (e.g., Ba1 or lower by Moodys) or by the investment adviser. In choosing securities, the funds investment adviser seeks to maximize current income by utilizing a flexible investment process that identifies opportunities in the municipal bond market of any maturity, duration and credit quality, including below investment grade securities. The investment advisers credit research department analyzes and monitors the securities that the fund owns or is considering buying. Under normal market conditions, the fund anticipates investing substantially in municipal bonds with remaining maturities of 5- to 30-years. The fund does not target a specific level of portfolio turnover as purchases and sales are made if the investment adviser determines the transactions will be advantageous to the fund. The fund may also invest in derivative instruments, principally futures contracts. The fund typically uses futures as a substitute for taking a position in the underlying asset or as a part of a strategy designed to reduce exposure to other risks. During unusual market conditions, the fund may invest entirely in taxable securities as a temporary defensive measure. When the fund engages in such activities, the fund would not be pursuing its investment strategy and, as a result, it may not achieve its investment objective. Show less