"The NFIP [National Flood Insurance Program] was established by the National Flood Insurance Act of 1968 (NFIA, 42 U.S.C. §4001 et seq.), and was most recently reauthorized to July 31, 2018, through a series of short-term reauthorizations. The general purpose of the NFIP is both to offer primary flood insurance to properties with significant flood risk, and to reduce flood risk through the adoption of floodplain management standards. Communities volunteer to participate in the NFIP in order to have access to federal flood insurance, and in return are required to adopt minimum standards. [..] Congress has provided appropriations to the NFIP for some of the cost of Risk MAP. Congress also authorizes the use of premium revenues for other NFIP costs, including administration, salaries, and other expenses. NFIP premiums also include other charges, such as a Federal Policy Fee, a Reserve Fund assessment, and a surcharge to help fund the NFIP. In October 2017, Congress cancelled $16 billion of NFIP debt, making it possible for the program to pay claims for Hurricanes Harvey, Irma, and Maria. The NFIP currently owes $20.525 billion to the U.S. Treasury, leaving $9.9 billion in borrowing authority from a $30.425 billion limit in law. This debt is serviced by the NFIP and interest is paid through premium revenues. After July 31, 2018, key authorities of the NFIP, such as the authority to issue new insurance contracts, will expire if they are not reauthorized by Congress."
CRS Report for Congress, R44593