Flood Zones A, AH, AO & AR: What They Mean for Your Home.
All four are high-risk zones on FEMA’s flood map, so if you have a mortgage, your lender will require flood insurance. What changes from letter to letter is how the water is expected to behave and how much detail the map gives — and both can affect your price.
- AH and AO mean shallow flooding: usually 1 to 3 feet of ponding or sheet flow
- Zone A is high risk with no base flood elevation on the map
- Zone AR means a levee or flood control system is being rebuilt
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What do flood zones A, AH, AO and AR mean?
All four are Special Flood Hazard Areas — places FEMA expects to have at least a 1% chance of flooding in any given year. Over a 30-year mortgage, that works out to about a 1-in-4 chance. The letters tell you what kind of flooding FEMA expects and how detailed the map is:
- Zone AH — shallow flooding where water ponds, usually 1 to 3 feet deep. The map shows a base flood elevation.
- Zone AO — shallow flooding where water runs across the ground in a sheet, usually 1 to 3 feet deep. The map shows a flood depth instead of an elevation.
- Zone A — high risk, mapped with approximate methods. No base flood elevation is shown.
- Zone AR — temporarily high risk while a levee or other flood control system is being restored.
If your map says AE, that’s the detailed version of Zone A — see our Zone AE guide. For the lower-risk zones, see Zone X and X500.
Flood zone AH: shallow ponding
Zone AH means water is expected to collect in low spots and pond, usually 1 to 3 feet deep. The map shows a base flood elevation, so an elevation certificate can show whether your floor sits above the expected water line — and many AH homes do.
Flood zone A: high risk, no elevation on the map
Zone A is high risk like AE, but FEMA mapped it with approximate methods and didn’t publish a base flood elevation. It’s common in rural areas and along smaller streams, and because the map is approximate, the line can be off in either direction.
Flood zone AO: shallow sheet flow
Zone AO means water is expected to run across the ground in a shallow sheet, usually 1 to 3 feet deep, often on sloping land. The map shows a flood depth instead of an elevation. It’s common on alluvial fans and at the foot of hills in the West.
Flood zone AR: a levee being rebuilt
Zone AR is a temporary high-risk zone for areas where a levee, dam or other flood control system is being restored. The system used to protect the area, no longer meets FEMA’s standards, and is being rebuilt to provide that protection again.
While the work is underway, flood insurance is still required with most mortgages. Once the system is finished and FEMA accredits it, the area can be remapped to a lower-risk zone. Until then, the risk is real — a levee under repair is still a levee under repair.
Is flood insurance required in zones A, AH, AO and AR?
Yes, if you have a mortgage from a federally regulated or federally backed lender. All four are Special Flood Hazard Areas, so the lender has to require flood insurance. A paid-off home isn’t required to carry it, but the risk doesn’t change.
- Required with most mortgages — in A, AH, AO and AR alike
- A LOMA can take a home out of the zone — if your home sits higher than the flood level, see how to get a LOMA
- Lenders can require it anywhere — some ask for flood insurance outside high-risk zones too
Not sure which zone you’re in? Look it up with our FEMA flood map tool or read how to check your flood zone by address.
How much does flood insurance cost in these zones?
There’s no single price for a zone. Since Risk Rating 2.0, the NFIP prices each home on its own: distance to water, elevation, foundation type, rebuild cost and the coverage you choose. Two AH homes on the same street can get very different quotes.
Private flood insurers use their own models, and in shallow-flooding zones like AH and AO they can come in lower than the NFIP. The only way to know is to price both — our private flood vs. NFIP comparison explains the trade-offs.
We shop both, for your exact address.
Send us the address. We check the zone, look at elevation, and compare the NFIP with the private markets that will write your home. Start a quote or call 1-866-990-7482.
Other flood zones, explained
Every letter on the flood map means something different for your coverage and your price. Here are our plain-English guides to the rest:
Not sure which zone you’re in? Use our FEMA flood map tool or see how to check your flood zone by address.
Zone A, AH, AO and AR questions, answered straight
What do flood zones A, AH, AO and AR mean?
All four are high-risk Special Flood Hazard Areas with at least a 1% chance of flooding each year. AH means shallow ponding, AO means shallow sheet flow, A means high risk mapped without a base flood elevation, and AR means a levee or flood control system is being restored.
Do I need flood insurance in Zone A, AH, AO or AR?
Yes, if you have a mortgage from a federally regulated or federally backed lender. All four are Special Flood Hazard Areas, so the lender has to require flood insurance.
What is flood zone AR?
Zone AR is a temporary high-risk zone for areas where a levee, dam or other flood control system is being restored. Flood insurance is still required with most mortgages until the system is finished and the area is remapped.
Which is worse, Zone AE or Zone AH?
Both are high-risk zones with a 1% yearly flood chance. AH flooding is expected to be shallow ponding, usually 1 to 3 feet, while AE covers deeper flooding along rivers, lakes and coasts. What matters most for your price is how high your home sits.
How do I find out which flood zone I’m in?
Look up your address on FEMA’s flood map, or use our FEMA flood map tool. Your lender’s flood zone determination will also list it.
In Zone A, AH, AO or AR? Let’s price it.
Send us the address. A real Flood Nerd checks your zone and elevation, shops the NFIP and the private market, and sends back one clear recommendation.
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