Why Some Counties Show Over 100% Flood Insurance Compliance

A denominator problem, not a compliance miracle

To compute what share of legally-required flood insurance is actually in force, FEMA needs two numbers per county: how many NFIP policies are active in the mapped flood zone, and how many residential structures exist there to be covered. The second number is the weak link, FEMA's own count of that denominator is missing for roughly 805 of the 3144 counties in this dataset, and for a smaller set (27 counties) the reported structure count is smaller than the number of active policies, which arithmetically produces a compliance rate over 100%.

What it looks like in real counties

Tarrant County, TX's raw NFIP figures would compute to roughly 228% compliance; Pinellas County, FL comes out over 1,000%. Neither means Tarrant or Pinellas homeowners are radically over-insured, it means FEMA's residential structure count for the mapped zone in those counties understates the real number, likely from a stale or incomplete parcel count feeding that denominator. This site reports those counties as "unreliable" rather than showing a rate that implies near-universal or impossible compliance.

Why not just hide the affected counties

Silently dropping roughly a quarter of US counties from a "flood insurance compliance" map would misrepresent coverage as complete when it isn't. Instead, every affected county still gets its hazard score, its voluntary (all-structure) insurance rate where available, and an honest note that the mandated-zone compliance figure specifically cannot be trusted, see any flagged county's page for the caveat in context.

Where to go next

See the range this plays out across: Los Angeles County, CA, Charlevoix County, MI, Loving County, TX.

What the Special Flood Hazard Area (SFHA) Actually Means · Embed the FloodZoneFinder Flood Risk Badge