What does flood zone A mean?

Zone A is a high-risk flood area with a 1% chance of flooding in any given year, mapped with approximate methods, so FEMA has not published a base flood elevation for it. It is part of the Special Flood Hazard Area.

Is flood insurance required in zone A?

If the building has a mortgage from a federally regulated or insured lender and the community participates in the NFIP, the lender must require flood insurance. Your lender or a licensed agent can confirm the requirement for your loan.

What is the difference between zone A and zone AE?

Both are 1% annual chance floodplains. Zone AE was mapped with a detailed study and shows a base flood elevation; zone A was mapped with approximate methods and does not.

Flood zone A: what it means for your home and insurance

High risk (Special Flood Hazard Area)Also shown as Zone A, Approximate A zone

Inside the 1% annual chance floodplain, mapped with approximate methods, so no base flood elevation is published.

Free property report with the FEMA flood zone plus wildfire, wind, earthquake and landslide risk. Open the full address analyzer.

What zone A means

Zone A marks land FEMA expects to flood in the base flood: the flood with a 1% chance of happening in any given year. It is part of the Special Flood Hazard Area.

Zone A areas were mapped with approximate analysis rather than a detailed hydraulic study, so the map does not show a base flood elevation (BFE) — the height floodwater is expected to reach. Without a BFE, it is harder to know how high a building needs to be to stay dry.

FEMA calls the flood with a 1% chance of being equaled or exceeded in any given year the "base flood" (often called the 100-year flood). A 1% chance each year adds up: over 30 years it works out to roughly a 26% chance of at least one such flood.

Insurance in zone A

This is a Special Flood Hazard Area (SFHA). Under federal law, if you have a mortgage from a federally regulated or insured lender — or a loan backed by FHA, VA, USDA, Fannie Mae or Freddie Mac — on a building in an SFHA in a community that participates in the National Flood Insurance Program (NFIP), the lender must require flood insurance. Your lender or a licensed agent can confirm what your loan requires.

Standard homeowners policies exclude flood damage. Flood coverage is bought separately, either through the NFIP or from a private flood insurer.

Because no BFE is published, a surveyor may need to estimate one (FEMA publishes guidance for this) when preparing an Elevation Certificate. Your community floodplain administrator may already have a local estimate.

If you believe your building sits above the mapped flood level, a licensed surveyor or engineer can prepare an Elevation Certificate, and you can ask FEMA for a Letter of Map Amendment (LOMA) to remove the building from the SFHA.

Reducing flood risk

Ask your local floodplain administrator whether an estimated base flood elevation exists for your area.
Get an Elevation Certificate so you know how your lowest floor compares to the base flood elevation.
Raise furnaces, water heaters, electrical panels and HVAC equipment above expected flood levels.
Use flood-resistant materials (tile, concrete, closed-cell insulation) below the base flood elevation.
Install a backflow valve so floodwater cannot push sewage back into the house.
Grade soil away from the foundation and keep gutters, downspouts and drains clear.

Your community’s floodplain administrator can tell you which building requirements apply locally.

Zone A questions

What does flood zone A mean?: Zone A is a high-risk flood area with a 1% chance of flooding in any given year, mapped with approximate methods, so FEMA has not published a base flood elevation for it. It is part of the Special Flood Hazard Area.
Is flood insurance required in zone A?: If the building has a mortgage from a federally regulated or insured lender and the community participates in the NFIP, the lender must require flood insurance. Your lender or a licensed agent can confirm the requirement for your loan.
What is the difference between zone A and zone AE?: Both are 1% annual chance floodplains. Zone AE was mapped with a detailed study and shows a base flood elevation; zone A was mapped with approximate methods and does not.

Check the flood zone for any address

We look up the address in FEMA’s National Flood Hazard Layer and show the zone alongside the rest of the property’s risk profile.

Free property report with the FEMA flood zone plus wildfire, wind, earthquake and landslide risk. Open the full address analyzer.

Other flood zones

All FEMA flood zones

This page is general education about FEMA flood zone designations, not insurance or legal advice and not an offer of coverage. Zone definitions come from FEMA’s Flood Insurance Rate Maps; maps change, and the official map for any property is on the FEMA Flood Map Service Center. Your lender or a licensed agent can confirm the flood insurance requirements for a specific home.