A bill relating to the prevention of circumvention or diversion of antidumping and countervailing duty orders.

Amends the Tariff Act of 1930 to require the administering authority to consider, in addition to those factors already required, when determining whether imported parts or components of merchandise completed or assembled in the United States or a foreign country are circumventing an antidumping or countervailing duty order, the value and sources of supply of parts or components historically used in the assembly of the merchandise subject to such order.

Authorizes 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) it is completed or assembled in the United States or a foreign country from parts or components supplied by 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 value of the imported parts or components is significant in relation to the total value of all parts and components used in the assembly or completion operation, excluding packing; (3) consideration of specified factors establishes a pattern of circumvention of an antidumping or countervailing duty order; or (4) the administering authority determines that action is appropriate to prevent circumvention of such order. Enables the administering authority to base such a decision on any of such factors by itself, rather than on all of them together.