Millions don't have flood insurance "when they really should," an expert said. 'Never in a million years'Barker, along with most of her neighbors, did not have flood insurance. And because of this misconception, experts estimate that "tens of millions of Americans are not carrying flood insurance when they really should be," according to Crawford. This means that in some locations, First Street's analysis shows a different level of flood risk than FEMA's maps. But the data isn't public-facing; it can only be seen by current homeowners or by someone purchasing a flood insurance plan, and it isn't reflected in most of FEMA's readily available flood maps.