In this rule the Federal Emergency Management Agency (FEMA) proposes the implementation of the Cost Estimating Format (CEF) as the standard estimating procedure for large permanent work projects authorized under the Public Assistance program. FEMA also proposes to implement set ceiling and floor thresholds of plus or minus 10 percent. Under this rule, FEMA would reimburse an applicant for the portion of an overrun that is greater than the 10 percent ceiling threshold, but FEMA would not reimburse an applicant for an overrun that is more than the CEF estimate but less than the 10 percent ceiling threshold. If there is an underrun, an applicant would retain the portion of the underrun that is less than the 10 percent floor threshold to use for mitigation activities, but would return the portion of the underrun that is greater than the 10 percent floor threshold.