The different hazard mitigation programs are authorized by separate sections of the Robert T. Stafford Act. The Hazard Mitigation Grant Program is authorized by Section 404. Hazard mitigation funded by the Public Assistance Program is authorized by Section 406.
Section 406 focuses on mitigation measures for facilities that have actually been damaged in a particular disaster. Section 404 has a broader scope and funds mitigation projects for both damaged and non-damaged facilities.