FEMA flood zones explained

Q: What are the FEMA flood zones?

FEMA flood zones are risk areas shown on Flood Insurance Rate Maps (FIRMs). High-risk Special Flood Hazard Areas start with A (inland/riverine: A, AE, AH, AO, AR, A99) or V (coastal with wave action: V, VE). Moderate- and low-risk areas are Zone X (shaded = 0.2% annual chance, unshaded = minimal), and Zone D is undetermined risk. There are 11 designations covered here.

Q: In which flood zones is insurance mandatory?

Flood insurance is mandatory for a building with a federally backed mortgage in any high-risk Special Flood Hazard Area — every zone beginning with A or V. In Zone X and Zone D it is optional but recommended, since flooding still happens outside high-risk areas.

Q: What is the difference between Zone AE and Zone X?

Zone AE is a high-risk Special Flood Hazard Area with a 1%-annual-chance (100-year) flood and published Base Flood Elevations; insurance is usually mandatory and pricier. Zone X is moderate or minimal risk outside the high-risk area; insurance is optional and much cheaper.

Q: Does my flood zone set my premium?

Not directly anymore. Since FEMA's Risk Rating 2.0 (2023), premiums are priced on each property's own risk factors rather than the zone's flat rate. The zone still determines whether insurance is mandatory and signals overall risk.

FEMA flood zones are the risk areas drawn on Flood Insurance Rate Maps (FIRMs). The high-risk Special Flood Hazard Areas (SFHAs) have a 1%-annual-chance (100-year) flood and start with A (inland: A, AE, AH, AO, AR, A99) or V (coastal with wave action: V, VE). In these zones flood insurance is mandatory for a federally backed mortgage. Outside them, Zone X (shaded = the 0.2% / 500-year band, unshaded = minimal risk) and Zone D (undetermined) are not high-risk, so insurance is optional but still recommended. There are 11 designations explained below.

Source: FEMA — Flood Zones glossary & FIRM zone definitions. Data as of June 2026.

All 11 FEMA flood zones

Zone	Risk category	SFHA?	Insurance mandatory?	Annual chance
Zone A	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (100-year)
Zone AE	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (100-year)
Zone AH	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (100-year)
Zone AO	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (100-year)
Zone AR	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (temporarily increased)
Zone A99	High-risk (SFHA)	Yes	Yes (with mortgage)	1% (100-year)
Zone V	High-risk coastal (SFHA)	Yes	Yes (with mortgage)	1% (100-year) + wave action
Zone VE	High-risk coastal (SFHA)	Yes	Yes (with mortgage)	1% (100-year) + wave action
Zone X (shaded)	Moderate-risk	No	No	0.2% (500-year)
Zone X (unshaded)	Minimal-risk	No	No	< 0.2% (outside 500-year)
Zone D	Undetermined risk	No	No	Undetermined

Source: FEMA — Flood Zones glossary & FIRM zone definitions. Data as of June 2026.

High-risk zones (Special Flood Hazard Areas)

Insurance is mandatory in these zones with a federally backed mortgage:

Zone A

High-risk area subject to the 1%-annual-chance flood, with no detailed analysis, so no Base Flood Elevations (BFEs) are shown.

Zone AE

The most common high-risk zone: the base floodplain where Base Flood Elevations (BFEs) are determined and shown on the map.

Zone AH

High-risk shallow ponding flooding, typically 1-3 feet deep; BFEs are shown.

Zone AO

High-risk shallow sheet-flow flooding on sloping terrain, usually 1-3 feet deep; depths (not BFEs) are shown.

Zone AR

High-risk area behind a flood-control system (e.g. a levee) being restored, with a temporarily increased flood risk.

Zone A99

High-risk area that will be protected by a federal flood-control system under construction; no BFEs shown.

Zone V

High-risk coastal zone with additional wave-velocity hazard; no detailed BFEs shown.

Zone VE

Coastal high-risk zone with wave-velocity hazard where Base Flood Elevations are determined; highest-cost zone.

Moderate, minimal and undetermined-risk zones

Insurance is optional (but recommended) in these zones:

Zone X (shaded)

Moderate-risk area between the 1% and 0.2%-annual-chance (500-year) flood; insurance not federally required but recommended.

Zone X (unshaded)

Minimal-risk area outside the 0.2%-annual-chance (500-year) floodplain; insurance optional and lowest-cost.

Zone D

Areas where flood hazards are undetermined but possible; no flood analysis has been conducted.

Frequently asked questions

What are the FEMA flood zones?

FEMA flood zones are risk areas shown on Flood Insurance Rate Maps (FIRMs). High-risk Special Flood Hazard Areas start with A (inland/riverine: A, AE, AH, AO, AR, A99) or V (coastal with wave action: V, VE). Moderate- and low-risk areas are Zone X (shaded = 0.2% annual chance, unshaded = minimal), and Zone D is undetermined risk. There are 11 designations covered here.

In which flood zones is insurance mandatory?

Flood insurance is mandatory for a building with a federally backed mortgage in any high-risk Special Flood Hazard Area — every zone beginning with A or V. In Zone X and Zone D it is optional but recommended, since flooding still happens outside high-risk areas.

What is the difference between Zone AE and Zone X?

Zone AE is a high-risk Special Flood Hazard Area with a 1%-annual-chance (100-year) flood and published Base Flood Elevations; insurance is usually mandatory and pricier. Zone X is moderate or minimal risk outside the high-risk area; insurance is optional and much cheaper.

Does my flood zone set my premium?

Not directly anymore. Since FEMA's Risk Rating 2.0 (2023), premiums are priced on each property's own risk factors rather than the zone's flat rate. The zone still determines whether insurance is mandatory and signals overall risk.

Keep exploring

Source

Definitions: FEMA — Flood Zones glossary & FIRM zone definitions (US public domain). Check your property's exact zone at the FEMA Flood Map Service Center. General information, not insurance advice.

Last updated: 2026-06-20