Flood Zone Types Explained (Plain English)
FEMA assigns every US address a flood zone. Here is what each one means -- risk level, insurance requirement, and where it typically shows up.
Not sure which zone you are in? Check your address ->
All FEMA Flood Zones at a Glance
Sorted high-risk to low. Each zone code links to a full plain-English explainer.
| Zone | Risk (plain English) | Insurance required? | Where it typically is |
|---|---|---|---|
| AE | High risk -- The most common high-risk flood zone. Flood insurance is typically required for federally-backed mortgages. | Usually required | River valleys, urban floodplains, coastal lowlands |
| VE | High risk -- The highest-risk coastal flood zone. Wave action adds to storm-surge risk. Flood insurance is required for federally-backed mortgages. | Usually required | Ocean beachfronts, bay shores, coastal inlets where wave action is expected during a 100-year flood |
| A | High risk -- A high-risk flood zone similar to AE, but without a calculated Base Flood Elevation. Flood insurance is typically required. | Usually required | Areas with approximate (not detailed) FEMA flood studies -- often rural or recently developed areas |
| AO | High risk -- A shallow-flooding high-risk zone where water typically moves as sheet flow rather than rising in a channel. Flood insurance is required. | Usually required | Alluvial fans in the Southwest, areas below earthen dams, broad low-gradient floodplains |
| AH | High risk -- A shallow-ponding high-risk zone with a Base Flood Elevation. Flood insurance is required for federally-backed mortgages. | Usually required | Shallow ponding areas -- closed depressions, slow-draining basins, land behind drainage structures |
| X | Lower risk -- A low-risk flood zone outside the Special Flood Hazard Area. Flood insurance is not required but is often available at lower rates. | Not required | The majority of developed US land -- anywhere outside the mapped 1% and 0.2% annual chance floodplains |
| D | Not mapped / undetermined -- An unstudied zone where flood risk is not determined. Flood insurance is not required but is available. | Not required | Remote or newly developed areas where FEMA has not completed a flood hazard study |
- AE High risk The most common high-risk flood zone. Flood insurance is typically required for federally-backed mortgages. Usually required
- VE High risk The highest-risk coastal flood zone. Wave action adds to storm-surge risk. Flood insurance is required for federally-backed mortgages. Usually required
- A High risk A high-risk flood zone similar to AE, but without a calculated Base Flood Elevation. Flood insurance is typically required. Usually required
- AO High risk A shallow-flooding high-risk zone where water typically moves as sheet flow rather than rising in a channel. Flood insurance is required. Usually required
- AH High risk A shallow-ponding high-risk zone with a Base Flood Elevation. Flood insurance is required for federally-backed mortgages. Usually required
- X Lower risk A low-risk flood zone outside the Special Flood Hazard Area. Flood insurance is not required but is often available at lower rates. Not required
- D Not mapped / undetermined An unstudied zone where flood risk is not determined. Flood insurance is not required but is available. Not required
How FEMA Names Flood Zones
- A-family (AE, A, AO, AH)
- Riverine and inland high-risk zones. AE has a detailed study with a Base Flood Elevation; plain A uses an approximate study without one. AO and AH cover shallow-flooding scenarios.
- V-family (VE, V)
- Coastal high-hazard zones where wave action occurs during a major storm. The most stringent building standards apply here.
- Zone X
- Outside the high-risk boundary. Unshaded Zone X is outside both the 1% and 0.2% annual chance boundaries. Shaded Zone X sits between them (moderate risk).
- Zone D
- Unstudied area -- flood risk has not been determined. Not safe to assume low risk; just means FEMA has not mapped it yet.
Check YOUR Address
The table above tells you what each zone means in general. Only your address tells you which zone applies to YOUR home.