Strategy. Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in municipal bonds that pay interest exempt from federal income tax. These municipal bonds and other securities in which the Fund may invest may pay interest that is subject to the federal alternative minimum tax (AMT) for certain taxpayers. Although the Fund may invest in municipal bonds in any rating category, under normal conditions, the Fund invests at least 50% of its net assets in municipal bonds rated BBB+/Baa1 or lower (at the time of purchase), or an equivalent short-term rating, as applicable, by an independent rating agency or that are unrated but deemed by Lord, Abbett & … Show more… Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in municipal bonds that pay interest exempt from federal income tax. These municipal bonds and other securities in which the Fund may invest may pay interest that is subject to the federal alternative minimum tax (AMT) for certain taxpayers. Although the Fund may invest in municipal bonds in any rating category, under normal conditions, the Fund invests at least 50% of its net assets in municipal bonds rated BBB+/Baa1 or lower (at the time of purchase), or an equivalent short-term rating, as applicable, by an independent rating agency or that are unrated but deemed by Lord, Abbett & Co. LLC (Lord Abbett) to be of comparable quality, with a particular emphasis on lower rated municipal bonds (commonly referred to as below investment grade, high yield, or junk bonds), which are bonds that are rated BB+/Ba1 or lower (at the time of purchase), or an equivalent short-term rating, as applicable, by an independent rating agency or are unrated but deemed by Lord Abbett to be of comparable quality. The Fund may invest without limitation in unrated municipal bonds, which may constitute a significant portion of the Funds portfolio. The Fund also may invest in defaulted securities ( i.e., bonds on which the issuer has not paid principal or interest on time) and securities of issuers that are or may become involved in reorganizations, financial restructurings, or bankruptcy (commonly referred to as distressed debt). The Fund presently does not intend to invest more than 20% of its net assets (measured at the time of investment) in such defaulted or distressed securities. However, the Funds defaulted or distressed debt holdings may exceed this level from time to time if the Fund purchased securities that were not considered in default or distressed at their time of purchase and such securities subsequently become defaulted or distressed. These investment strategies are generally higher risk relative to strategies employed by funds that invest primarily in investment grade municipal bonds. The Fund may invest in all types of municipal bonds, including general obligation bonds, revenue bonds, municipal leases, and variable rate demand notes. The Fund may invest in both insured and uninsured municipal bonds. The Fund also may invest in zero coupon, deferred interest, pay-in-kind, and capital appreciation bonds. The Fund may invest up to 100% of its net assets in private activity bonds (commonly referred to as AMT paper), which are a type of municipal bond that pays interest that is subject to AMT. Although the Fund is permitted to invest up to 20% of its net assets in fixed income securities that pay interest that is subject to regular federal income tax, the Fund presently has no intention of investing in this manner. There is a risk that a bond issued as tax-exempt may be reclassified by the Internal Revenue Service (IRS) as taxable. The Fund will not invest more than 25% of its total assets in any industry; however, this limitation does not apply to tax-exempt securities and securities issued by the U.S. Government or its agencies or instrumentalities. Certain types of municipal securities (including general obligation, general appropriation, municipal leases, special assessment, and special tax bonds) are not considered a part of any industry for purposes of this industry concentration policy. Therefore, the Fund may invest more than 25% of its total assets in these types of municipal securities. The Fund may invest without limitation in securities of issuers located in a single state, territory, municipality, or region. The Fund may invest up to 100% of its net assets in inverse floaters (also known as residual interest bonds), which are a type of derivative investment that provides leveraged exposure to underlying municipal bonds whose interest payments vary inversely with changes in short-term tax-exempt interest rates. The Fund also may invest in other types of derivatives, such as futures, for non-hedging, hedging, or duration management purposes. The Fund may invest in individual securities of any maturity or duration. Normally, the Fund seeks to maintain a dollar-weighted average maturity of between ten and twenty-five years. The Funds portfolio management team focuses on credit risk analysis, tax exempt income yield, total return potential, interest rate risk, and call protection in managing its portfolio. The Fund may sell a security when the Fund believes the security is less likely to benefit from the current market and economic environment or shows signs of deteriorating fundamentals, among other reasons. The Fund may deviate from the investment strategy described above for temporary defensive purposes. The Fund may miss certain investment opportunities if defensive strategies are used and thus may not achieve its investment objective. Show less