This bill significantly amends the Robert T. Stafford Disaster Relief and Emergency Assistance Act to enhance predisaster hazard mitigation efforts by making assistance mandatory. It mandates that the President shall provide assistance for predisaster hazard mitigation measures, shifting from discretionary "may" to compulsory "shall" for several key provisions, including a minimum allocation for the National Public Infrastructure Predisaster Mitigation Fund. A central provision adjusts the Federal cost share for certain projects, mandating a federal contribution of not less than 90 percent for mitigation activities costing less than $1,000,000. Additionally, for critical facilities—such as emergency operation centers, healthcare facilities, and schools—with projects under $1,000,000, the President may contribute more than 90 percent of the total cost. The bill also expands eligibility and access to these vital programs by explicitly including Indian Tribes alongside States and local governments. It ensures Tribes can access assistance directly, through state recommendations, or via a dedicated Tribal-set aside of funds, with specific technical and financial assistance outlined to help them improve resilience and carry out innovative projects.