Flood Insurance When You Buy or Sell: The Policy You Inherit Is Not the Price You Keep

The appraisal cleared. You love the house. Then the lender's letter arrives with a line you skimmed past on every other property: the home sits in a Special Flood Hazard Area, and flood insurance has to be in place before the loan can fund. Or you are on the other side of the table, and the buyer's agent asks the question that makes every seller pause. Has this house ever flooded? Flood is the cost that hides behind the mortgage right up until the moment it can move a deal.

For most homes in America there is exactly one place to buy that coverage, and it is not a private insurer. It is the National Flood Insurance Program, created by the National Flood Insurance Act of 1968 and run by the Federal Emergency Management Agency, according to the Congressional Research Service. The program is enormous (more than 4.7 million policies covering over 1.3 trillion dollars across 22,000-plus communities, per FEMA) and, at the same time, almost invisible to the average buyer until a lender or a flood map forces the issue. Understanding how it prices, and where it is headed, is one of the least glamorous and most expensive parts of a home purchase.

The disclosure gap you can walk right into

Whether a seller has to tell you a house has flooded depends heavily on the state, and the rules are uneven. Some states require a written flood-history disclosure. Others ask almost nothing, and in those places a home that took water twice in the last decade can change hands with the buyer none the wiser. If you are buying, treat the seller's disclosure as a floor, not a ceiling. Pull the property's flood zone yourself from FEMA's maps, ask directly about past claims, and remember that federal law requires flood insurance on any federally backed mortgage inside a Special Flood Hazard Area. The zone is not a formality, it is a line in your budget.

Here is the caveat that cuts the other way. The map is not the risk. Only about 3.3 percent of United States households carry an NFIP policy, and take-up ranges from over 20 percent in Louisiana and nearly 18 percent in Florida down to under 1 percent across more than two dozen states. Plenty of flooding happens to homes that were never in a mapped high-risk zone and never bought coverage. A clean flood-zone letter tells you the lender will not require a policy. It does not tell you the basement stays dry. Skipping that distinction is one of the more expensive home-buying mistakes people make, because it is invisible until the water arrives.

The policy you inherit is not the price you keep

Now the part almost nobody prices correctly. In many cases an NFIP policy can be assumed by the buyer at sale, and that can be a real advantage, because of how the program now sets rates.

In 2021 and 2022 FEMA rolled out Risk Rating 2.0, an overhaul it branded "Equity in Action" that replaced a rating method largely unchanged for about fifty years. Phase 1 took effect October 1, 2021 for new policies and voluntary renewals, Phase 2 on April 1, 2022 for everyone else. Instead of pricing a home to its flood-zone map, it prices each home to its own full risk. It was widely misreported as a blanket rate hike, and for many lower-value homes that had been overpaying it actually brought decreases. But for the exposed coastal and riverfront properties that buyers most often worry about, "priced to full risk" generally means up.

What keeps that increase from landing all at once is a set of legal caps. Under the 2014 Homeowner Flood Insurance Affordability Act, most primary-residence premiums can rise no more than 18 percent per year until they reach the property's full-risk rate, at which point they stop. Non-primary residences, businesses, and severe-repetitive-loss homes face a higher ceiling of up to 25 percent per year. A policy that has been climbing that glide path for a few years sits well below where it is heading. Assume the seller's policy and you often step onto that same spot on the ladder, below full risk, instead of being freshly rated.

That is the saving. It is also the trap. If you budget around the premium you inherit, you are budgeting around a number that is legally scheduled to climb 18 percent a year, and possibly 25, until it reaches a full-risk figure the seller never had to pay. The cheap policy is a snapshot of someone else's place in line, not your steady-state cost. Ask the current premium, ask the full-risk target, and plan for the gap.

Why the program is in the red, and why that touches your budget

None of this pricing pressure is an accident, and you can read the reason straight off the program's balance sheet. The NFIP owes the United States Treasury about 22.5 billion dollars. In October 2017, facing Harvey, Irma, and Maria, Congress cancelled 16 billion dollars of that debt in the first forgiveness in the program's history, and within eight years the balance was back above where it started, including another 2 billion dollars borrowed in February 2025 after Hurricanes Helene and Milton.

The debt exists because the program is required by law to charge some homes less than their risk costs, and to phase in increases slowly with those 18 and 25 percent caps. That is Congress choosing affordability over solvency, year after year, and the debt is the running receipt. For a buyer, the takeaway is simple and slightly uncomfortable. Today's flood premiums are politically compressed and legally scheduled to keep rising toward the real number. There is one more practical wrinkle worth knowing. The NFIP runs on short-term reauthorizations and has lapsed briefly more than once. A lapse can stall the flood-insurance binding a closing depends on, so if you are buying in a flood zone, it is worth confirming the program is active before you set a hard closing date.

The 25-year cost, not the closing line item

The mistake is filing flood insurance under closing costs, a one-time number you clear and forget. It behaves more like a tax that reprices every year, which is exactly why it helps to price insurance like a property tax and run it across the whole time you expect to own the home. A premium rising 18 percent a year roughly doubles in four years and more than doubles again in eight. Over a typical hold, the flood line can quietly outgrow several of the costs you fussed over at the inspection.

It is not evenly spread, either. The Government Accountability Office reports that repetitive-loss properties are only about 2.5 percent of NFIP policies but account for roughly 48 percent of claims by dollar value. A small set of homes floods over and over, and those are precisely the addresses where full-risk pricing bites hardest. If the house you are buying is one of them, the escalating premium is not a rounding error on the hidden costs of a resale home, it is one of the largest of them.

What it does to you at resale

Then the wheel turns and you become the seller. The premium you accepted is now the number your buyer's lender underwrites and your buyer's agent negotiates against. A high or fast-climbing flood premium narrows your pool of buyers, invites price concessions, and shows up in the same disclosure conversation you once sat on the other side of. Flood risk does not just widen your cost of ownership, it follows the house to the closing table and reappears as a discount when you try to leave. This is the broader dynamic behind the 2026 home insurance crisis: coverage that used to be a quiet background cost is now a live variable in what a home is worth.

The honest read

The NFIP is worth seeing whole. Measured as an insurer it is insolvent by design, propped up by a Treasury credit line and periodic forgiveness. Measured as public infrastructure it is close to irreplaceable, the only reason millions of people can hold a mortgage in a flood zone at all. For a buyer or a seller, neither verdict is really the point. The point is that flood is a real, rising, and legally scheduled cost, and the worst thing you can do is treat the premium on the current policy as the premium you will pay. Price the glide path, not the snapshot, and the house either still makes sense or it does not, on numbers you can actually see.

If you want the longer version of how costs like this hide inside a home and resurface the day you try to sell, it is the whole subject of my book, The Resale Trap.

Amazon