This bill revises Section 844 of the William M. (Mac) Thornberry National Defense Authorization Act for Fiscal Year 2021, which concerns the Department of Defense's acquisition of certain metal products. The primary change is to the applicability date of the prohibition on acquiring these materials from specific nations. This prohibition will now apply only to contracts entered into on or after the earlier of January 1, 2032 , or 180 days after the Secretary of Defense certifies the availability of sufficient alternative suppliers outside of covered nations. Additionally, the bill formally incorporates definitions for "covered material" and "covered nation" by referencing existing statute to clarify the scope of the prohibition. Finally, it requires the Secretary of Defense to update the Department of Defense Supplement to the Federal Acquisition Regulation within 120 days to reflect these amendments.