Amendments

The program was first amended by the Flood Disaster Protection Act of 1973, which made the purchase of flood insurance mandatory for the protection of property within SFHAs. In 1982, the Act was amended by the Coastal Barrier Resources Act (CBRA). The CBRA enacted a set of maps depicting the John H. Chafee Coastal Barrier Resources System (CBRS) in which federal flood insurance is unavailable for new or significantly improved structures. The National Flood Insurance Reform Act of 1994 codified the Community Rating System (an incentive program that encourages communities to exceed the minimal federal requirements for development within floodplains) within the NFIP. The program was further amended by the Flood Insurance Reform Act of 2004, with the goal of reducing "losses to properties for which repetitive flood insurance claim payments have been made."

The Biggert–Waters Flood Insurance Reform Act of 2012 (Biggert-Waters) modified the NFIP. At the conclusion of 2011, as Congress passed Biggert-Waters, the NFIP cumulative debt was over $17 billion. A core principle of Biggert-Waters was to change the NFIP premiums to match actuarial risk-based premiums that better reflected the expected losses and real risk of flooding. These changes included removing discounts to many policies which were being sold below actual actuarial risk targets and eliminating "grandfathering" of older rates.

In January 2014, the United States Senate passed the Homeowner Flood Insurance Affordability Act of 2014. This bill changed the process used to alter subsidized premiums and reinstated grandfathering of lower rates; effectively delaying the increases in flood insurance premiums to obtain risk-based premiums under Biggert-Waters and spreading the cost of the lost premiums over all of the remaining policy holders.

The National Flood Insurance Program was $24 billion in debt at the beginning of 2014 as a result of Hurricanes Katrina, Rita and Sandy. The passage of the HFIAA described above has concerned insurance and environmental observers that the delay in implementation of actuarial rates will leave taxpayers exposed to additional losses.