Flood is an exclusion in standard homeowners policies. Not limited, not subject to a higher deductible. Excluded outright. The same is true of renters and condo policies.
This is the single most consequential gap in residential property insurance, and it is the one people discover after the water has already been in the house.
What counts as a flood
The distinction that decides which policy responds is not how much water there is. It is where the water came from.
Generally covered by a homeowners policy: water that arrives from above or from inside. Rain coming through a roof the wind has just torn open. A burst supply pipe. An overflowing water heater. A sudden appliance failure.
Generally excluded as flood: water that rises or spreads across the ground. Storm surge. A river or creek leaving its banks. Surface water accumulating after heavy rain. Mudflow. Water that comes up through the ground into a basement.
The awkward middle case is rain that enters a house that was already open. Wind tears off shingles, then rain enters through the opening. That is usually a wind claim, because wind created the opening. Rain that simply accumulates on the ground and then enters the house is flood.
After a coastal storm this becomes the wind versus water question, and it decides which policy pays and which deductible applies. Damage from wind and damage from surge in the same house from the same storm are handled by two separate policies.
A third category catches people out entirely: sewer and drain backup, which is covered by neither a standard homeowners policy nor a flood policy. Most insurers sell it as an endorsement, and it is worth asking about regardless of your flood exposure.
How flood coverage is bought
Most residential flood coverage comes through the National Flood Insurance Program (NFIP), run by FEMA. You do not buy it from FEMA directly. It is sold through insurance agents and through participating insurers under the Write Your Own program, where private companies issue and service NFIP policies.
One useful consequence of that structure: NFIP rates do not vary by who sells them. The same NFIP policy on the same property costs the same regardless of which agent or participating company writes it. Shopping around changes your service experience, not the NFIP premium.
A growing private flood insurance market also exists, both as an alternative to the NFIP and as excess coverage above NFIP limits. Private policies are not bound by the NFIP's caps or rules, so their terms, limits and waiting periods differ and need to be read on their own terms.
What the NFIP covers, and its limits
NFIP coverage is capped by statute. These are the current maximums.
| Property type | Building coverage | Contents coverage |
|---|---|---|
| Residential | Up to $250,000 | Up to $100,000 |
| Non-residential | Up to $500,000 | Up to $500,000 |
Manufactured and mobile homes are eligible on the same residential basis, up to $250,000 building and $100,000 contents.
Building and contents are separate purchases. Buying building coverage alone, which is what a lender's requirement often amounts to, leaves your belongings uncovered.
There is an important difference in how the two settle. NFIP building coverage can be written on a replacement cost basis for a primary residence meeting the program's conditions, but contents coverage is available only on an actual cash value basis. There is no replacement cost option for personal property under the NFIP. Depreciation is deducted, which for furniture, electronics and appliances can be substantial. This is one of the most common sources of disappointment in a flood claim, and it is a structural feature of the program rather than an insurer decision.
If your home is worth more than the NFIP building cap, excess flood coverage from the private market is the usual route to closing the difference.
Basements and areas below grade
The NFIP restricts what it pays for in basements, crawlspaces and other areas below the lowest elevated floor, and the restriction is tighter than most people assume.
Building coverage in those areas is generally limited to structural elements and essential building equipment such as furnaces, water heaters, electrical panels and sump pumps. Personal property kept in a basement is very limited, and finished elements such as carpeting, drywall finishing, and built-in furniture are largely excluded.
If you store anything of value in a basement, this is worth confirming in detail before assuming it is covered.
The waiting period, and its four exceptions
This is the timing trap. An NFIP policy generally takes effect 30 days after purchase.
You cannot buy coverage as a storm approaches and have it apply to that storm. You cannot increase coverage once a flood has begun. Policies do not cover losses from a flood that occurred before the policy took effect.
FloodSmart lists four exceptions to the 30-day wait:
- No waiting period when the policy is purchased in connection with making, increasing, extending or renewing a mortgage loan.
- No waiting period when coverage is changed at policy renewal.
- A one-day waiting period when the property is newly designated in a high-risk flood zone and the policy is purchased within 12 months of the map update.
- A one-day waiting period when the flood is caused or worsened by a wildfire on federal land, and the policy is purchased within 60 days of the wildfire containment date.
That fourth exception exists because burn scars dramatically increase flood and mudflow risk in the seasons after a fire.
NFIP policies run for one year, with a 30-day grace period after expiration during which a claim will still be honored if you renew and pay in full within that window.
Given the 30-day rule, the decision about flood coverage is one to make in a quiet month, not during a forecast.
Who should think about it
Two facts undercut the most common reason people skip it.
Flood maps describe risk, they do not confine it. Properties outside high-risk zones flood regularly. A designation of moderate or low risk means lower assessed probability, not immunity, and a meaningful share of flood claims come from outside the high-risk zones.
Maps change. Development upstream, new construction, changed drainage and remapping all shift the picture over time. A property mapped out of a high-risk zone years ago may not be today.
Anyone with a mortgage on a property in a designated high-risk zone will generally be required by the lender to carry flood coverage. That requirement sets a floor, not an adequate amount, and it typically addresses only the building.
Renters can buy contents-only NFIP coverage. Renters policies exclude flood the same way homeowners policies do, and the belongings in a ground-floor or basement apartment are exposed.
Questions worth asking
- Am I in a designated flood zone, and when was my area last remapped?
- Does my lender require coverage, and is that requirement building only?
- Am I buying contents coverage as well, and do I understand it settles at actual cash value?
- Is my building coverage enough, given the NFIP cap and what it would cost to rebuild?
- What is limited in my basement or crawlspace?
- Would private or excess flood coverage make sense above the NFIP limits?
- Do I have sewer and drain backup coverage, which neither policy includes?
FEMA and your state's Department of Insurance are the authorities on program rules, and a licensed agent can tell you what applies to your specific address.
Related reading: what homeowners insurance covers, hurricane, wind and hail deductibles, and actual cash value vs replacement cost.
NFIP program rules, coverage limits and waiting period exceptions are set by federal statute and program regulation and can change. Private flood policies differ. Coverage, exclusions and eligibility vary by insurer and by property, and the policy documents control. Confirm anything specific to your home with a licensed agent, FEMA, or your state's Department of Insurance. You can also request home insurance quotes and get connected with licensed providers who cover your area.