U.S. note 2(a)
(a) For the purposes of heading 9903.01.01, products of Mexico, other than products described in headings 9903.01.02, 9903.01.03, 9903.01.04, 9903.01.05, 9903.76.01, 9903.76.02 or 9903.76.03 and other than products for personal use included in accompanied baggage of persons arriving in the United States, shall be subject to an additional 25% ad valorem rate of duty. Notwithstanding U.S. note 1 to this subchapter, all products of Mexico that are subject to the additional ad valorem rate of duty imposed by heading 9903.01.01 shall also be subject to the general rates of duty imposed on products of Mexico entered under subheadings in chapters 1 to 97 of the tariff schedule. The additional duties imposed by heading 9903.01.01 apply to products of Mexico including both goods of Mexico under the rules set forth in part 102, title 19 of the Code of Federal Regulations, as applicable, as well as goods for which Mexico was the last country of substantial transformation prior to importation into the United States. Products of Mexico that are eligible for special tariff treatment under general note 3(c)(i) to the tariff schedule, or that are eligible for temporary duty exemptions or reductions under subchapter II to chapter 99, shall be subject to the additional ad valorem rate of duty imposed by heading 9903.01.01. The additional duties imposed by heading 9903.01.01 shall not apply to goods for which entry is properly claimed under a provision of chapter 98 of the tariff schedule pursuant to applicable regulations of U.S. Customs and Border Protection ("CBP"), and whenever CBP agrees that entry under such a provision is appropriate, except for goods entered under heading 9802.00.80; and subheadings 9802.00.40, 9802.00.50, and 9802.00.60. For subheadings 9802.00.40, 9802.00.50, and 9802.00.60, the additional duties apply to the value of repairs, alterations, or processing performed (in Mexico), as described in the applicable subheading. For heading 9802.00.80, the additional duties apply to the value of the article assembled abroad (in Mexico), less the cost or value of such products of the United States, as described. Products of Mexico that are provided for in heading 9903.01.01 shall continue to be subject to antidumping, countervailing, or other duties, taxes, fees, exactions and charges that apply to such products, as well as to the additional ad valorem rate of duty imposed by heading 9903.01.01.