Yes. For permanent work on insurable buildings, contents, equipment and vehicles, you must obtain and keep insurance against the hazard that caused the damage, in an amount based on eligible costs before reductions. If you don’t, FEMA denies or deobligates the funds and the facility is ineligible in future disasters.
Proof of coverage by type and amount, or a letter of commitment. See FEMA Recovery Policy FP 206-086-1.
Track obtain-and-maintain obligations in a register by facility and disaster. A lapse years later can claw back old funding and bar future help.