​Pre-Firm buildings constructed prior to March 1979 are considered “pre-FIRM” and those constructed on or after March 1, 1979 are considered “post-FIRM.”

A Pre-FIRM Building is a building for which construction or substantial improvement occurred on or before the effective date of an initial Flood Insurance Rate Map (FIRM). For Sacramento County, pre-FIRM applies to buildings constructed prior to March 1979.

A Post-FIRM building is a building for which construction or substantial improvement occurred after the effective date of an initial Flood Insurance Rate Map. For Sacramento County, post-FIRM applies to buildings constructed on or after March 1, 1979.