The Mitigation Directorate, a component of the http://ow.ly/d/7kdV Federal Emergency Management Agency (FEMA), manages the National Flood Insurance Program (NFIP). The three components of the NFIP are Flood Insurance, Floodplain Management, and Flood Hazard Mapping. NFIP makes Federally backed flood insurance available to homeowners, renters, and business owners in these communities.
Here is a booklet published by FEMA called "Answers to Questions About the National Flood Insurance Program". The first two chapters are very helpful if you have any questions about how it works - http://bit.ly/2oiur6W.