44 CFR §67.10

1. (a)Until such time as a final determination is made and proper notice is given, no person within a participating community shall be denied the right to purchase flood insurance at the subsidized rate.
2. (b)After the final determination and upon the effective date of a FIRM, risk premium rates will be charged for new construction and substantial improvements. The effective date of a FIRM shall begin not later than six months after the final flood elevation determination.