Skip to content
Flood Figures

The flood insurance glide path: how the 18% annual cap works

Federal law caps how fast an existing NFIP policy’s premium can rise at renewal: for most individual policies, no more than 18% per year, and for certain statutorily defined classes, 25% per year, until the premium reaches the building’s full-risk price. The multi-year climb this produces is known as the glide path. It is a description of current law — the Homeowner Flood Insurance Affordability Act of 2014 (HFIAA), codified at 42 U.S.C. §4015 — not a prediction about any particular policy.

Why a glide path exists

The National Flood Insurance Program historically charged many buildings less than the price its own rating system considered full-risk — pre-FIRM buildings (built before their community’s first flood map) received subsidized rates by statute, and remapped buildings could keep old-zone pricing through grandfathering. The Biggert-Waters Act of 2012 ordered those subsidies phased out, in some cases abruptly; HFIAA in 2014 replaced the abrupt schedule with capped annual increases. Risk Rating 2.0 then made the full-risk price building-specific. The combined result: every policy has a current premium and a full-risk premium, and the caps govern the closing of any gap between them.

The caps, precisely

  • 18% individual cap. The chargeable premium for a policy on a primary residence generally may not increase more than 18% over the prior year (42 U.S.C. §4015(e)).
  • 25% classes. Statute requires increases of 25% per year until full-risk rates are reached for certain categories: non-primary residences, severe repetitive loss properties, business properties, and buildings substantially damaged or improved (42 U.S.C. §4014(g)).
  • 15% class average. Across each risk class, the average increase in a year is limited to 15% (42 U.S.C. §4015(e)) — a constraint on FEMA’s rate-setting in aggregate, layered under the individual caps.
  • Surcharges sit outside the caps. The HFIAA surcharge ($25 for primary residences, $250 for other properties) and the Reserve Fund assessment are added to the capped premium, which is why a bill can move slightly differently than the capped percentage alone implies. This site reports premium and total policy cost separately for this reason — see how much is flood insurance?

A policy already at its full-risk premium simply pays that price; the caps bind only while a gap exists. (Full-risk prices themselves can also change when FEMA revises rates or the building’s characteristics change — the caps then govern the approach to the new figure.)

What preserves a glide path — and what resets one

The glide path belongs to the policy, not the owner. Consequences that follow from current FEMA rules:

  • Sale of the building. The seller’s policy may be assigned to the buyer at closing, keeping its current premium and its position on the glide path. A buyer who instead purchases a new policy starts at the building’s full-risk price. The mechanics are in the assumable flood policies guide.
  • Lapse. Allowing a policy to lapse can forfeit the discounted position; re-purchasing later generally means full-risk pricing. (Narrow statutory exceptions exist, such as lapses caused by a lapse of the program’s own authorization — see the NFIP lapse FAQ.)
  • Substantial improvement. Renovating a building beyond the 50%-of-market-value threshold, or repairing substantial damage, moves it into the 25% class and can end pre-FIRM treatment — the threshold mechanics appear in the ICC guide.
  • Coverage changes. Increasing coverage limits adds premium priced at full-risk rates for the increment.

Reading the data with the glide path in mind

Premium statistics mix policies at full-risk prices with policies still climbing. Two otherwise identical buildings can appear in FEMA’s records at different premiums because one policy is older than the other — a data artifact of the caps, visible in the medians and means on this site’s state pages (Florida, Texas, Louisiana) and ZIP pages. The methodology page documents what the premium fields contain.

Frequently asked questions

Does the 18% cap mean every premium rises 18% every year?

No. The cap is a ceiling, not a schedule. A policy at its full-risk premium is not climbing at all, and FEMA’s aggregate increases are further bound by the 15% class-average limit.

How long does a glide path last?

Until the policy’s premium reaches the building’s full-risk price. The duration depends on the size of the initial gap and the applicable cap — statute sets the per-year limits, not an end date.

Can a buyer keep the seller’s flood insurance price?

Under NFIP rules, yes — by assuming the seller’s policy at closing rather than buying a new one. See assumable flood policies.

Do the caps apply to private flood insurance?

No. The HFIAA caps govern NFIP chargeable premiums. Private flood insurers file their own rates under state insurance law — one of the structural differences covered in NFIP vs. private coverage differences.

Where do the 18/25/15 numbers come from?

Directly from statute: 42 U.S.C. §4015(e) (18% individual cap and 15% class average) and §4014(g) (25% classes), as amended by HFIAA 2014.

Sources

Related pages