To limit the exceptions to certain "Buy American" requirements, and to expand such requirements.

Amends the Department of Defense Appropriations Act, 1993 to: (1) remove certain exceptions from the prohibition against the use of Department of Defense funds for the procurement of certain items not grown, reprocessed, reused, or produced in the United States; and (2) require the Secretary of the military department concerned to certify that satisfactory quality and sufficient quantity of such an item cannot be procured as and when needed from U.S. suppliers or that an emergency exists and the procurement is vital to national security and the item is grown, reprocessed, reused, or produced in a country that adheres to fair labor practices.

Provides that, in determining whether a purchase is for an amount greater than the simplified acquisition threshold, multiple purchases of a similar item in a fiscal year shall be deemed a single purchase. Prohibits Defense Commissary Agency purchases of articles or items in excess of such threshold when not grown, reprocessed, reused, or produced in the United States.