LOMA / LOMR

Letters of Map Amendment and Letters of Map Revision are FEMA's instruments for changing flood-map facts between full restudies. A LOMA typically removes a structure or lot from the mapped floodplain on elevation evidence — the land was above the flood level all along, and a survey proves it. A LOMR revises the map itself where physical changes or better studies justify redrawing boundaries or elevations.

The letters matter practically: a LOMA can lift the mandatory insurance purchase requirement for a structure the map painted in. They are also records — parcel-specific, dated, and cumulative — so a lot's flood status is properly read as map plus letters, not the map alone.