Strategy. Under normal market conditions, the Portfolio invests at least 80% of the sum of its net assets and the amount of any borrowings for investment purposes in municipal bonds that pay interest that is exempt from regular federal personal income tax. Regular federal personal income tax is different from, and does not include, the federal alternative minimum tax. These municipal bonds include obligations issued by U.S. states and their subdivisions, authorities, instrumentalities and corporations, as well as obligations issued by U.S. territories (such as Puerto Rico, the U.S. Virgin Islands and Guam) that pay interest that is exempt from regular federal personal income tax. The Portfolio may invest without limit in securities that generate income subject to the alternative minimum … Show more… Under normal market conditions, the Portfolio invests at least 80% of the sum of its net assets and the amount of any borrowings for investment purposes in municipal bonds that pay interest that is exempt from regular federal personal income tax. Regular federal personal income tax is different from, and does not include, the federal alternative minimum tax. These municipal bonds include obligations issued by U.S. states and their subdivisions, authorities, instrumentalities and corporations, as well as obligations issued by U.S. territories (such as Puerto Rico, the U.S. Virgin Islands and Guam) that pay interest that is exempt from regular federal personal income tax. The Portfolio may invest without limit in securities that generate income subject to the alternative minimum tax on individuals, therefore, the Portfolio may not be suitable for investors subject to the federal alternative minimum tax on individuals. The Portfolio invests in various types of municipal securities, including investment grade (rated BBB/Baa or better), below investment grade (rated BB/Ba or lower), and unrated municipal securities. The Portfolio may invest up to 50% of its net assets in below investment grade municipal bonds, but will normally invest 10-30% of its net assets in such bonds. Such securities are commonly referred to as high yield securities or junk bonds. The Portfolio may invest up to 5% of its net assets in defaulted bonds. The Portfolio will focus on securities with intermediate to longer term maturities and, as such, will generally maintain, under normal market conditions, an investment portfolio with an overall weighted average maturity of approximately 12 to 25 years. The Portfolio may invest in all types of municipal bonds, including general obligation bonds, revenue bonds and participation interests in municipal leases. The Portfolio may invest in zero coupon bonds, which are issued at substantial discounts from their value at maturity and pay no cash income to their holders until they mature. The Portfolio may invest up to 50% of its net assets in municipal securities whose interest payments vary inversely with changes in short-term tax-exempt interest rates ( inverse floaters ). Inverse floaters are derivative securities that provide leveraged exposure to underlying municipal bonds. The Portfolios investments in inverse floaters are designed to increase the Portfolios income and returns through this leveraged exposure. These investments are speculative, however, and also create the possibility that income and returns will be diminished. The Portfolio will only invest in inverse floating rate securities whose underlying bonds are rated A or higher. The Portfolio may also make forward commitments in which the Portfolio agrees to buy a security for settlement in the future at a price agreed upon today. The Portfolios sub-adviser uses a value-oriented strategy and looks for higher-yielding and undervalued municipal bonds that offer the potential for above-average total return. The sub-adviser may choose to sell municipal bonds with deteriorating credit or limited upside potential compared to other available bonds. Developed exclusively for use within separately managed accounts advised or sub-advised by Nuveen Asset Management, LLC, the Portfolio is a specialized municipal bond portfolio to be used in combination with selected individual securities to effectively model institutional-level investment strategies. The Portfolio enables certain Nuveen municipal separately managed account investors to achieve greater diversification and return potential than might otherwise be achieved by using lower quality, higher yielding securities. Show less