Treats State and local officials who honor certain DHS detainer requests as acting on behalf of the Department of Homeland Security for liability purposes, substitutes the United States as the defendant in related state lawsuits, and limits plaintiffs to remedies under federal law. It defines "sanctuary jurisdiction" as a State or locality that restricts sharing or honoring information or DHS detainer/release-notification requests, with a narrow exception for victims and witnesses.

Makes jurisdictions labeled as "sanctuary" ineligible for specified federal grants (including certain Economic Development Administration and Community Development Block Grant funds), requires return and reallocation of funds if a grantee becomes a sanctuary jurisdiction, and sets those eligibility changes to take effect on October 1, 2025.