What Does a 9 Out of 10 Flood Factor Mean?
It means the property faces the highest flood risk level. A separate flood policy is worth checking.
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Why this number matters before you close
A flood factor of 9 is scored on a 1 to 10 scale. It means the property has a high chance of flooding over the life of a 30-year mortgage, based on rainfall, storm surge, and nearby water. This score comes from a modeling source outside your homeowners policy, not from the insurer writing your coverage. Your homeowners policy will not pay for flood damage no matter what this score says, since flood is excluded on a standard policy. The lender may or may not require flood insurance, and that depends on whether the house sits in a federally mapped flood zone, which is separate from this score. Ask the lender directly whether flood insurance is required. Get a flood insurance quote too, so you know the cost before closing.
Get both quotes before you close
Homeowners insurance won't cover flood damage, and a 9 out of 10 score means that risk is real. Comparing a homeowners quote alongside a flood quote now shows the full cost before closing day.
Where this score actually comes from
The number comes from a model that looks at rainfall patterns, storm surge, river and coastal flooding, and local drainage over a 30-year window. It is not pulled from FEMA's flood maps, and it is not something the insurer writing your homeowners policy calculated. Two houses on the same street can carry different scores because the model looks at ground elevation and water flow property by property, not just by zone.
Lenders usually check the federal flood maps to decide if flood insurance is required, not this score. A house can show a 9 out of 10 and still sit outside the federally designated high-risk zone. That means the lender might not require coverage even though the modeled risk is high. The reverse happens too. A property can fall inside a mapped flood zone, triggering a lender requirement, while scoring lower on this particular model. The two systems measure similar things but answer different questions, and closing on a house means dealing with whatever the lender's answer is.
If flood insurance turns out to be optional in your case, a 9 out of 10 is still worth taking seriously. Flood policies through the National Flood Insurance Program often have a waiting period before coverage starts, typically around 30 days, so buying one the week before closing can leave a gap. Private flood insurers sometimes offer faster start dates, which is worth asking about if the timeline is tight. Pricing it out now, rather than after move-in, means no surprise if the lender's underwriting turns up a requirement late in the process.
One more thing worth checking is whether the seller already has a flood policy in place. Some flood policies can be assigned to the buyer at closing and may carry a lower rate tied to the property's claims history. That is a question for the seller or the closing agent, not something either quote will tell you. It costs nothing to ask, and it can shortcut the waiting period if the existing policy transfers cleanly.
How this score affects what you pay and what shows up later
A 9 out of 10 doesn't change your homeowners premium by itself. Insurers pricing a standard policy aren't pulling this particular score into their math, since it comes from a separate modeling source and flood isn't part of what that policy covers anyway. What it does affect is the flood policy, if you end up needing or wanting one. A property modeled at this level of risk tends to cost more to insure against flood than one modeled lower, though the exact number depends on elevation, construction, and the specific flood zone designation, not the score alone.
Worth checking before closing is whether this house has flooded before. Sellers are often required to disclose prior flood damage or past insurance claims tied to flooding, and that disclosure should be sitting in your closing documents somewhere. A high score plus a documented history of past flooding is a different situation than a high score with no history. Ask the closing agent where that disclosure is if you haven't seen it yet.
It's also worth finding out whether the score is likely to climb over time rather than hold steady. Some of these models project risk forward as sea levels, rainfall patterns, or local drainage capacity change over the coming decades. A property at 9 now could be modeled even higher in ten years, which matters if you're planning to stay long-term rather than sell in a few years. The model's own report, if the lender or a flood insurer shares it, usually breaks out current risk versus projected risk separately.
None of this changes what's required to close. The lender's requirement comes from the federal flood map determination, and that's the document that decides whether flood insurance is mandatory. This score is a separate piece of information, useful for deciding whether to carry flood coverage even when it isn't required, and useful for understanding what you're buying into. Treat it as one more fact to weigh, not as the number that drives the paperwork.
Before you lock in coverage
Check the lender's flood zone determination, not just this score, to see if flood insurance is required. Then get a flood quote alongside your homeowners quote so the full cost is settled before closing.
