Section 406 Hazard Mitigation in FEMA Public Assistance

Section 406 hazard mitigation — usually shortened to "406 mitigation" — is additional Public Assistance funding for resilience work performed on a disaster-damaged facility while it is being repaired. FEMA's published Public Assistance Program and Policy Guide (PAPPG) Version 5 describes PA hazard mitigation as measures that help avoid repetitive damage from multiple disasters, reduce the potential for future damage to an eligible facility, and provide long-term solutions to increasingly frequent and severe natural hazards. Approved measures are considered part of the total eligible cost of the repair, restoration, or reconstruction project — not a separate grant.

That is the core difference from Section 404. Section 406 mitigation attaches to a specific PA permanent work project on a damaged facility. Section 404 of the Stafford Act creates the Hazard Mitigation Grant Program (HMGP), a separate, capped funding stream for cost-effective measures in any area affected by the major disaster — including facilities the disaster never touched. An applicant may use both programs on the same facility, but never for the same work.

What 406 mitigation covers — and what it does not

Stafford Act Section 406 authorizes federal contributions for the repair, restoration, reconstruction, or replacement of public and eligible private nonprofit facilities damaged by a major disaster. The PAPPG explains that FEMA calls PA hazard mitigation "406 mitigation" because that section funds cost-effective measures that increase the resilience of disaster-damaged facilities against future incidents. Under 44 CFR § 206.226(e), FEMA's Regional Administrator may even require cost-effective hazard mitigation measures not required by applicable standards, and the cost of any FEMA-required mitigation is an eligible cost.

Mitigation is work beyond codes and standards. Upgrades required to meet eligible codes and standards are part of restoration work, not mitigation. Where a proposed resilience measure exceeds a code requirement, FEMA evaluates only the above-code portion as mitigation. Separately, Section 406(e) requires eligible repair costs themselves to be estimated in conformity with the latest consensus-based codes and standards that incorporate hazard-resistant design — so a well-built project stacks code-based resilience and 406 mitigation on top of each other.

Two structural limits apply. First, PA hazard mitigation may only be included in permanent restoration work — Categories C through G — never in emergency work projects. Second, the recipient (state, tribe, or territory) must have a current hazard mitigation plan approved under 44 CFR Part 201 before FEMA can provide PA funding for any permanent work; plans must be updated every five years.

Eligibility: protect the damaged portions

Under PAPPG v5, a measure is eligible for PA hazard mitigation funding when it directly reduces the potential for future damage to the damaged portion(s) of the facility, meets cost-effectiveness criteria, and complies with all federal, state, local, tribal, and territorial legal requirements, including Environmental and Historic Preservation (EHP) laws. FEMA also evaluates technical feasibility and effectiveness, and checks that the measure does not negatively impact the facility's operation or surrounding areas or create susceptibility to damage from another hazard.

Eligible measures are generally performed on the damaged portions themselves, though they may also protect other parts of the facility. Measures that are separate and distinct from the damaged portion are evaluated on how they protect the damaged portion. The PAPPG's examples include:

• Floodwalls or vegetated swales constructed around damaged facilities;
• New drainage structures — culverts or permeable pavements — along a damaged road;
• Fire-resistant materials and defensible space around eligible facilities; and
• Dry floodproofing of damaged and undamaged buildings that hold functionally interdependent components of one system.

If FEMA determines a measure is ineligible as PA mitigation — for example, it protects only undamaged portions — the applicant may request HMGP funding for those portions instead. And a warning worth flagging early: if FEMA approves PA mitigation funding and the applicant does not complete the mitigation work, FEMA will deobligate those funds.

The three cost-effectiveness paths

Cost-effectiveness is required by 44 CFR § 206.226(e), and PAPPG v5 gives three alternative ways to demonstrate it. A measure qualifies if any one of the following is met:

1. The 15 percent path. The measure's cost does not exceed 15 percent of the total eligible repair cost — calculated prior to any insurance reductions — of the facility or facilities the measure applies to.
2. The Appendix J path (up to 100 percent). The measure is specifically listed in PAPPG Appendix J, "Cost-Effective Public Assistance Hazard Mitigation Measures," and its cost does not exceed 100 percent of the eligible repair cost (again, pre-insurance). Appendix J covers categories such as upsized or realigned culverts, bridge restraint cables and deck tie-downs, seismic bracing and elevation of mechanical/electrical/plumbing components, pipe joint restraints, submersible pumps, and generator quick-connects. Version 5 expanded Appendix J with additional measures, including two focused on wildfire.
3. The benefit-cost analysis (BCA) path. The applicant or recipient demonstrates cost-effectiveness through an acceptable BCA methodology using FEMA's BCA Toolkit. The BCA compares the measure's total estimated cost against expected benefits to society: reduced facility and contents damage, reduced need for emergency protective measures and temporary facilities, reduced loss of function, casualties avoided (typically for earthquake, tornado, and wildfire measures), and documented previous impacts — even from events that were never federally declared. If a measure fails the first two tests, FEMA and the applicant work together to develop a BCA.

One nuance from v5: mitigation measures can address all hazards, not just the hazard that caused the damage.

406 vs. 404 at a glance

Because the two programs are complementary, a common pattern is 406 funding for the damaged portions and HMGP for undamaged portions of the same facility — permitted so long as the funds never pay for the same work.

Proposing 406 mitigation — and what happens after repairs

An applicant, recipient, or FEMA may recommend PA hazard mitigation measures for a project. Measures are added to permanent work projects through hazard mitigation proposals (HMPs), and applicants may request help from FEMA hazard mitigation staff to identify and develop them. Engineering analysis and design services — including surveys — to develop a proposal are fundable when the work is in the approved mitigation scope and has been completed.

Timing matters but is forgiving in both directions. If an applicant had to repair a facility quickly and missed the mitigation window, measures implemented on a completed PA-funded repair may still be eligible — but FEMA will not pay for duplicative work triggered by the later mitigation (tearing back into a finished repair, for example). Conversely, mitigation implemented after the incident but before the declaration or FEMA's evaluation may still be eligible if it is cost-effective and FEMA confirms EHP compliance.

Funding mechanics: shares, insurance, and capped projects

The federal share for Section 406 assistance is not less than 75 percent, and the statute allows a sliding scale up to 85 percent for states and tribes that invest in resilience measures. It also cuts the other way: § 406(b)(2) directs a reduced share — as low as 25 percent — for a facility damaged more than once in the preceding ten years by the same type of event whose owner failed to implement appropriate mitigation.

On insurance: the cost-effectiveness percentages are computed on repair costs prior to any insurance reductions, and even where insurance fully covers the eligible repair, mitigation may still be eligible if the total eligible project cost — including the mitigation — meets the minimum project threshold. See insurance and duplication of benefits for how reductions apply.

Capped ("flexible restoration") projects have their own rules. Improved projects that replace or relocate a facility can include mitigation funding, but FEMA deobligates the mitigation funds if the work is not completed or the original facility is replaced or relocated. For alternate projects, PA mitigation costs are excluded from the capped amount. Under Section 428 alternative procedures, approved mitigation is a separate fixed-cost amount within the subaward, cost-effectiveness is assessed against the fixed amount for restoring the facility to pre-disaster condition, and if capacity is increased the mitigation scope is limited to protecting the facility at its original capacity. If approved mitigation is not completed on a fixed-cost project, FEMA reduces the fixed amount by the mitigation portion.