The "First Responders Emergency Assistance Act" establishes a grant program through the Federal Emergency Management Agency (FEMA) to assist state, tribal, territorial, and local law enforcement and first responder agencies. This program aims to help these entities respond to substantial and rapid increases in the arrival or presence of aliens who have recently entered the United States. Eligible entities include law enforcement agencies, emergency operations centers, and other first responder agencies.

Grant funds can be used for various purposes, including the purchase and maintenance of equipment, as well as covering personnel costs such as salaries, overtime, and backfill positions for law enforcement and first responder personnel. Additionally, funds may support other appropriate activities or costs incurred in direct response to these increased arrivals, as determined by the Secretary of Homeland Security. A significant provision mandates that at least 25 percent of the appropriated funds must be awarded to eligible entities located in states sharing a border with Canada or Mexico.

The Administrator is tasked with establishing guidelines to ensure proper use of grant amounts, increase the proportion of funds used for operational expenses, and improve program performance reporting. For a five-year period, FEMA, in coordination with U.S. Customs and Border Protection and U.S. Customs and Immigration Enforcement, must submit annual reports and provide briefings to Congress. These reports will detail how grant funds were expended, the nature of operations supported, and recommendations for improving the program, including the potential for multi-year grants. Crucially, the bill explicitly states that appropriated funds may not be used to reimburse eligible entities for costs related to the enforcement of Federal immigration laws.