Subheading 9802.00.80, Harmonized Tariff Schedule of the United States (HTSUS), (19 U.S.C. 1202), provides that articles assembled abroad in whole or in part of fabricated components, the product of the United States, which (a) were exported in condition ready for assembly without further fabrication, (b) have not lost their physical identity in such articles by change in form, shape, or otherwise, and (c) have not been advanced in value or improved in condition abroad except by being assembled and except by operations incidental to the assembly process such as cleaning, lubricating, and painting, are subject to a duty upon the full value of the imported article, less the cost or, if no charge is made, the value of such products of the United States. The rate of duty which is assessed upon the dutiable portion of the imported article is that which is applicable to the imported article as a whole under the appropriate provision of the HTSUS (19 U.S.C. 1202) for such article. If that provision requires a specific or compound rate of duty, the total duties assessed on the imported article are reduced in such proportion as the cost or value of the returned United States components which qualify for the exemption bears to the full value of the assembled article.

A transistor radio is assembled abroad from foreign-made components and American-made transistors. Upon importation, the transistor radio is subject to the ad valorem rate of duty applicable to transistor radios upon the value of the radio less the cost or value of the American-made transistors assembled therein.

A solid-state watch movement is assembled abroad from foreign-made components and an American-made integrated circuit. If the movement in question is subject to the specific rate of duty of 75 cents if the value of the assembled movement is $30, and if the value of the American-made integrated circuit is $10, then the value of the integrated circuit represents one third of the total value of the assembled article and the duty on the assembled article will be reduced by one third ($.25). Therefore, the duty on the assembled movement is 50 cents.