To improve the enforcement of the antidumping and countervailing duty laws, and for other purposes.

Amends the Tariff Act of 1930 to authorize the administering authority to include within the scope of an antidumping or countervailing duty order imported parts or components that constitute certain merchandise sold in the United States and subject to such order, provided: (1) such merchandise is completed or assembled in the United States or a foreign country from parts or components sourced from the exporter or producer, from suppliers that have historically supplied such parts or components to such exporter or producer, or from any party in the exporting country supplying such items on behalf of such exporter or producer; (2) the difference between the value of such imported parts and components and the total value of all parts or components used in the assembly or completion operation, excluding packing, is small; or (3) consideration of specified factors establishes a pattern of circumvention of a countervailing or antidumping duty order or finding. Enables the administering authority to base such a decision on any of such factors by itself, rather than on all of the them together.

Requires the administering authority, when determining whether imported parts or components are circumventing such a duty order, to consider among other things the value and sources of supply of parts or components historically used in completion or assembly of the merchandise subject to the order.