The fund normally invests at least 80% of assets in municipal securities whose interest is exempt from federal income tax (but may be subject to the federal alternative minimum tax). It normally invests at least 80% of assets in securities included in the Fidelity Systematic U.S. Municipal Bond IndexSM, which aims to increase exposure to municipal bonds with higher risk-adjusted performance and liquidity characteristics relative to traditional market-capitalization weighted U.S. investment grade municipal bond indices.