About 6 million more U.S. homes are at risk of flooding than FEMA’s maps show, by one estimate — and some of those maps are two decades old | Fortune

Roughly 6 million additional U.S. properties face flood risk beyond what FEMA’s maps indicate, according to a new estimate, with some of the agency’s maps two decades out of date. The gap matters because FEMA maps underpin flood insurance requirements, mortgage lending decisions and disaster planning, so outdated boundaries can leave homeowners and lenders underestimating exposure. The finding adds pressure on federal and state officials to update mapping data as climate-driven flooding patterns shift. Watch for whether FEMA accelerates map revisions and how insurers and lenders adjust underwriting in areas newly identified as at risk.