FEMA and ICC 500 shelter standards, explained
No shelter is "FEMA approved"
FEMA does not endorse, approve or certify contractors or products, and companies may not claim to be "FEMA approved" or "FEMA certified" (FEMA Safe Rooms page). Treat that phrase as a warning sign.
What the standards are
- FEMA P-320: FEMA's homeowner guide to residential safe rooms, with prescriptive plans (FEMA P-320 (2025)).
- FEMA P-361: FEMA's design criteria for safe rooms, also used for FEMA-funded projects (FEMA P-320 (2025)).
- ICC 500: the building-code standard for storm shelters. Shelter door assemblies must be listed and labeled to show ICC 500 compliance (FEMA P-320 (2025)).
Who signs off on the design
FEMA does not verify or certify design calculations or products. The licensed design professional who signs the certification attests that the design meets the requirements, and FEMA recommends involving one because the P-320 prescriptive plans are not a substitute for that professional. FEMA also tells buyers to contact their local building official about code requirements (FEMA Safe Rooms page).
Grant-funded shelters
Prefabricated residential safe rooms paid for with FEMA funds must now show compliance with FEMA P-361 (2021) and ICC 500-2020; the grace period for older editions ended January 1, 2024. FEMA P-361 fifth edition applies to prefabricated residential subapplications under declarations or funding notices published on or after January 1, 2027 (FEMA Safe Rooms page).
Documents to ask for
- The ICC 500 label on the door assembly (and on the unit, for prefabricated shelters) (FEMA P-320 (2025))
- Signed and sealed construction documents, which the 2021 and 2024 IRC require for permits unless the unit is a listed and labeled prefab (FEMA P-320 (2025))
- The manufacturer's minimum foundation and anchoring requirements, which should go to you and the installer and be submitted with the permit (FEMA foundation and anchoring criteria)
- For OKC in-ground and slope-top shelters, the engineer's flotation letter (see permits)
Questions for installers
- Which edition of ICC 500 does this unit meet?
- Who designed it, and can I see the sealed drawings?
- Will my existing garage slab meet the anchoring specs, or does it need new concrete?
Checked Oct 23, 2026.
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