Aggregated uninsured residential flood losses across the US could exceed $375 billion under a 1-in-100-year flood scenario and surpass $1 trillion in rarer, higher-severity events, according to a new interactive whitepaper from Moody's.
The analysis provides county-level granularity on flood exposure and insurance take-up across the US, revealing a risk landscape that extends well beyond the coastal states most commonly associated with flood damage.
The findings expose a growing protection gap shifting catastrophic financial risk onto households, local governments and public balance sheets nationwide.
While counties with the largest potential uninsured losses — those exceeding $5 billion — are concentrated in Florida, Louisiana, South Carolina and Texas, the Moody's findings make clear that flood risk is no longer confined to a handful of high-profile coastal markets. In rarer 1-in-500-year events, total aggregated uninsured residential losses could triple compared with a 1-in-100-year scenario, spreading concentrated risk into additional inland states including Illinois and Pennsylvania.
Most US counties carry some level of flood exposure combined with high insurance protection gaps — a combination Moody's identified as a rising credit risk for local governments that would face fiscal strain after a severe event with limited federal or private sector backstop.
Hurricane Helene illustrated the problem in stark terms. The storm struck the southeastern US in September 2024, caused more than 230 fatalities, and brought catastrophic flooding across Florida, Georgia, the Carolinas, Tennessee and Virginia. In inland areas affected by the hurricane, fewer than 1% of properties had flood insurance.
The Moody's findings sit within a broader pattern of chronic underinsurance that the US flood market has consistently failed to address.
A December 2024 study by the Federal Reserve Bank of Philadelphia found that of an estimated $24.4 billion in annual flood-related damage to single-family homes across the US, only around 30% is insured, leaving roughly $17.1 billion in losses absorbed annually by uninsured households. Only 4% of US homeowners carry flood insurance.
Over the period from 2000 to 2024, total insured flood losses amounted to $319 billion, while uninsured losses topped $1.58 trillion, according to the report.
Current projections in the Moody's analysis indicate uninsured flood losses could rise by a further 25% by 2050 if insurance take-up rates and resilience investment remain unchanged.
That trajectory reflects both the physical reality of intensifying weather patterns and the persistent failure of the US flood insurance market to reach households outside mandatory coverage zones. Texas flooding in 2025 generated estimated economic losses of between $18 billion and $22 billion, most of it uninsured.
Private insurers have begun moving into the space, with results that challenge the assumption that flood is uninsurable at scale. In 2024, approximately $500 million in private residential flood premium was written alongside $750 million in private commercial flood business. A decade ago, private insurers held roughly 13% of the flood market by direct premiums written. By 2024, that share had risen to approximately 27%.
The Moody's data reinforces a well-established but persistently underacted-upon point: a significant share of residential clients in markets well outside traditional flood zones carry material uninsured exposure.
Without a meaningful shift in market behavior, the gap between insured and economic flood losses will continue to widen — and the financial consequences will fall disproportionately on the households and municipalities least equipped to absorb them.
