U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.

Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.

The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Glossary

Terms frequently used by FEMA. In a few instances, standard insurance industry terms have been added for additional focus and emphasis.
2 (1) | A (37) | B (15) | C (56) | D (36) | E (26) | F (57) | G (10) | H (19) | I (18) | J (4) | L (20) | M (25) | N (51) | O (18) | P (46) | R (35) | S (59) | T (12) | U (16) | V (13) | W (11) | Z (9)
Term: Zone

A geographical area shown on a Flood Hazard Boundary Map (FHBM) or a Flood Insurance Rate Map (FIRM) that reflects the severity or type of flooding in the area.

Glossary Section: NFIP - National Flood Insurance Program
Term: Zone A

Areas subject to inundation by the 1-percent-annual-chance flood event generally determined using approximate methodologies. Because detailed hydraulic analyses have not been performed, no Base Flood Elevations (BFEs) or flood depths are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (b) - Zone A Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone A99

Areas subject to inundation by the 1-percent-annual-chance flood event, but which will ultimately be protected upon completion of an under-construction Federal flood protection system. These are areas of special flood hazard where enough progress has been made on the construction of a protection system, such as dikes, dams, and levees, to consider it complete for insurance rating purposes. Zone A99 may only be used when the flood protection system has reached specified statutory progress toward completion. No Base Flood Elevations (BFEs) or depths are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (c)(9) - Zone A99 Requirements
  • 61.12 - Requirements for Designation
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone AE and A1-30

Areas subject to inundation by the 1-percent-annual-chance flood event determined by detailed methods. Base Flood Elevations (BFEs) are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (c) - Zone AE and A1-30 Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone AH

Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually areas of ponding) where average depths are between one and three feet. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (c) - Zone AE and A1-30 Requirements
    • (d) - Floodway Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone AO

Areas subject to inundation by 1-percent-annual-chance shallow flooding (usually sheet flow on sloping terrain) where average depths are between one and three feet. Average flood depths derived from detailed hydraulic analyses are shown in this zone. Mandatory flood insurance purchase requirements and floodplain management standards apply.

Some Zone AO have been designated in areas with high flood velocities such as alluvial fans and washes. Communities are encouraged to adopt more restrictive rquirements for these areas.

National Flood Insurance Program Requirements

  • 60.3 (c) (7) - Zone AO Requirements
    • (c)(8) - Zone AO Subdivision Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone AR

Areas that result from the decertification of a previously accredited flood protection system that is determined to be in the process of being restored to provide base flood protection. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (f) - AR Zone Requirements
  • 64.3 - Definition
  • 65.14 - Procedures
  • Flood Map
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone VE and V1-30

Areas subject to inundation by the 1-percent-annual-chance flood event with additional hazards due to storm-induced velocity wave action. Base Flood Elevations (BFEs) derived from detailed hydraulic analyses are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (e) - V Zone Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program
Term: Zone V

Areas along coasts subject to inundation by the 1-percent-annual-chance flood event with additional hazards associated with storm-induced waves. Because detailed hydraulic analyses have not been performed, no Base Flood Elevations (BFEs) or flood depths are shown. Mandatory flood insurance purchase requirements and floodplain management standards apply.

National Flood Insurance Program Requirements

  • 60.3 (e) - V Zone Requirements
  • 64.3 - Definition
Glossary Section: NFIP - National Flood Insurance Program

Would you like to take a brief survey regarding your experience with fema.gov?