Pauses tax filing deadlines, penalties, interest, and refund time limits for U.S. nationals who were unlawfully or wrongfully detained abroad or taken hostage by treating the detention/hostage period as excluded when calculating timeliness. It requires federal agencies to identify affected individuals and share that information with the Treasury so the IRS can update systems, ignore the detention time in timeliness calculations, and notify eligible people about refunds or abatements.

Creates a Treasury-administered refund and abatement program (in coordination with the State Department and Attorney General) that lets identified individuals apply for refunds or relief of penalties, interest, and additions to tax for the affected period, extends filing windows for those claims, and applies to taxable years ending after enactment with certain agency reporting deadlines (including a reporting requirement by January 1, 2026).