Strategy. The Fund, under normal circumstances, invests at least 80% of its assets (net assets plus borrowings for investment purposes) in municipal bonds that are rated investment grade by at least one nationally recognized statistical rating organization (NRSRO). Municipal bonds are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. On average, the Fund will invest in municipal bonds that have a maturity range of 10 to 30 years. Municipal bonds … Show more… The Fund, under normal circumstances, invests at least 80% of its assets (net assets plus borrowings for investment purposes) in municipal bonds that are rated investment grade by at least one nationally recognized statistical rating organization (NRSRO). Municipal bonds are issued to raise money for a variety of public and private purposes, including general financing for state and local governments, financing for eligible non-profit organizations, or financing for a specific project or public facility. Municipal securities usually pay a fixed, variable, or floating rate of interest, and must repay the amount borrowed, usually at the maturity of the security. On average, the Fund will invest in municipal bonds that have a maturity range of 10 to 30 years. Municipal bonds are issued by or on behalf of the District of Columbia, states, territories, commonwealths and possessions of the United States and their political subdivisions and agencies, authorities and instrumentalities. Municipal bonds include, among other instruments, general obligation bonds, revenue bonds, industrial revenue bonds, industrial development bonds, private activity bonds, as well as short-term, tax-exempt obligations such as municipal notes and variable rate demand obligations. The Fund may invest up to 20% of its net assets in unrated securities deemed by MacKay Shields LLC, the Fund's Subadvisor, to be of comparable quality. The Fund may not invest more than 20% of its net assets in tax-exempt securities subject to the federal alternative minimum tax. If NRSROs assign different ratings to the same security, the Fund will use the higher rating for purposes of determining the securitys credit quality. The Fund may invest more than 25% of its total assets in municipal bonds that are related in such a way that an economic, business or political development or change affecting one such security could also affect the other securities (for example, securities whose issuers are located in the same state). Some of the Fund's earnings may be subject to federal tax and most may be subject to state and local taxes. The Fund may invest in derivatives, such as futures, options and swap agreements to seek enhanced returns or to reduce the risk of loss by hedging certain of its holdings. Investment Process: The Subadvisor employs a relative value research-driven approach in pursuing the Fund's investment objective. The Subadvisor's strategies include duration management, sector allocation, yield curve positioning and buy/sell trade execution. The Subadvisor may engage in various portfolio strategies to achieve the Fund's investment objective, to seek to enhance the Fund's investment return and to seek to hedge the portfolio against adverse effects from movements in interest rates and in the securities markets. The Subadvisor uses active management in an effort to identify mispriced tax-exempt securities and build a consistent yield advantage. The Subadvisor focuses on reducing volatility through a disciplined investment process which includes fundamental, "bottom-up" credit research and risk management. In addition, the Subadvisor reviews macroeconomic events, technicals in the municipal market, tax policies and analyzes individual municipal securities and sectors. The Subadvisors investment process includes a risk analysis that gives consideration to a variety of security-specific risks, including but not limited to, environmental, social and governance (ESG) risks that may have a material impact on the performance of a security. In addition to proprietary research, the Subadvisor may use screening tools and, to the extent available, third party data to identify ESG risk factors that may not have been captured through its own research. The Subadvisors consideration of ESG risk is weighed against other criteria and no sectors or industries are explicitly excluded from the Fund. The Subadvisor may sell a security if it no longer believes the security will contribute to meeting the investment objective of the Fund. In considering whether to sell a security, the Subadvisor may evaluate, among other things, the condition of the economy and meaningful changes in the issuer's financial condition. Show less