Delaware Investments National Municipal Income Fund is a fixed-income mutual fund that aims to attain its goals by investing in the United States' fixed-income markets. It invests mainly in municipal obligations with an investment grade, tax-exempt from federal taxes, such as airport revenue bonds and hospital revenue bonds. The fund benchmarks its portfolio against the Barclays Municipal Bond Index and Lipper CE General & Insured Municipal Debt Funds (Leveraged) Average.