U.S. Defines 'U.S. Content' for Steel, Aluminum, Copper Tariffs from Canada and Mexico

The U.S. Department of Commerce's Bureau of Industry and Security (BIS) issued detailed guidance to U.S. Customs and Border Protection (CBP) on October 14, 2026, clarifying the assessment of “U.S. content” for purposes of implementing tariffs on steel, aluminum, and copper imports from Canada and Mexico under the United States-Mexico-Canada Agreement (USMCA)[1][3]. This guidance, effective for products entered or withdrawn from warehouse for consumption on or after 12:01 a.m. Eastern Time on October 14, 2026, specifies how a 25% tariff will apply only to the non-U.S. portion of these products[1][2][3].

This clarification directly impacts importers, customs brokers, and businesses that rely on integrated North American supply chains. The new definition of “U.S. content” will alter how tariffs are calculated, requiring adjustments to valuation support, sourcing records, and documentation processes for eligible imports from Canada and Mexico, potentially reducing tariff costs for some sectors[5][6][12].

What the records show

The core of the new BIS guidance, published as Federal Register Document 2026-20938, addresses how “U.S. content” is to be assessed for products from Canada and Mexico that qualify for preferential tariff treatment under USMCA[1][10]. Presidential Proclamation 11032, issued on June 1, 2026, stipulates that a 25% tariff will apply only to the non-U.S. content of such products, with the total effective duty on the imported product not being less than 15% ad valorem[1][2][5]. This proclamation directed the Secretary of Commerce to issue specific guidance to CBP regarding this assessment[1].

BIS has defined “U.S. content” in two principal ways[1][2][5][11]:

First, it includes the value of the product attributable to parts that were wholly obtained, entirely produced, or substantially transformed within the United States[1][2][5][11].

Second, to the extent not already accounted for in the first point, it includes the value of the product attributable to steel that was melted and poured in the United States, aluminum that was smelted and cast in the United States, or copper that was smelted and cast in the United States[1][2][5][11].

This updated guidance allows U.S.-made steel, aluminum, and copper to qualify for tariff relief even when these metals are incorporated into foreign components[6]. The proclamation also includes provisions for penalties if CBP determines an importer has engaged in fraud or deliberately misled the U.S. Government regarding U.S. content[5]. Questions regarding the application of this notice to a specific product may be directed to U.S. Customs and Border Protection[1].

The timeline

The foundation for these tariffs was established earlier in 2026. On April 2, 2026, President Donald J. Trump issued Proclamation 11021, titled “Strengthening Actions Taken to Adjust Imports of Aluminum, Steel, and Copper into the United States”[9]. This proclamation, which became effective on April 6, 2026, imposed additional Section 232 duties ranging from 10% to 50% on the full customs value of certain metal imports and their derivatives from all countries[9].

Two months later, on June 1, 2026, President Trump issued Presidential Proclamation 11032, titled “Further Adjusting the Tariff Regimes for Imports of Aluminum, Steel, and Copper Into the United States”[1][7]. This proclamation (91 FR 34085) modified previous tariff regimes and expanded product coverage to include items such as aluminum lithographic plates and steel racks, which are now treated as derivative products[1][8]. Proclamation 11032 also directed the Secretary of Commerce to issue specific guidance to CBP regarding the assessment of “U.S. content” for implementing tariffs pursuant to its clause (2)(d)[1]. The changes introduced by Proclamation 11032 became effective for goods entered or withdrawn from warehouse for consumption on or after 12:01 a.m. Eastern Time on June 8, 2026, and are slated to remain in effect through December 31, 2027[8].

Following Proclamation 11032, CBP issued its initial implementation guidance on June 5, 2026, through Cargo Systems Messaging Service (CSMS) #68855869[5][9]. This message provided instructions to importers, brokers, and filers on submitting entries under the updated tariff regime[9]. The most recent development, the detailed definition of “U.S. content” by BIS, was published in the Federal Register on October 14, 2026, becoming effective on the same date[1][3].

What changed and for whom

This specific guidance from BIS has immediate implications for a range of stakeholders involved in North American trade. U.S. Customs and Border Protection is directly affected as the primary recipient of this guidance, responsible for its accurate implementation at ports of entry[1]. The guidance dictates how CBP officers will evaluate the domestic content of imported metals to apply tariffs correctly.

Importers of steel, aluminum, and copper articles, as well as their derivative products, originating from Canada and Mexico and seeking USMCA preferential treatment, are directly impacted[5]. For these businesses, the clarification provides a definitive method for calculating the dutiable portion of their goods. Industries like the RV sector may see reduced tariff costs on USMCA-eligible equipment due to the new definition, as U.S.-made metals can now count toward tariff relief even if incorporated into foreign-made parts[6]. This represents a significant shift from previous interpretations.

Customs brokers and filers who manage these import entries will need to review and potentially adjust their valuation support, sourcing records, and documentation processes to comply with the new definition of “U.S. content”[12]. The change requires careful attention to how components are sourced and declared to ensure compliance and benefit from potential tariff reductions[12].

Businesses with integrated North American supply chains face added complexity due to the evolving tariff environment[13]. Companies that move components between the United States, Canada, and Mexico before importing finished products will need to re-evaluate their supply chain strategies and documentation to accurately account for U.S. content[13]. The guidance reinforces the importance of precise classification and sourcing strategies[8].

What the subject has said publicly

President Donald J. Trump publicly issued Proclamation 11032 on June 1, 2026, which established the framework for adjusting tariffs and directed the Secretary of Commerce to define “U.S. content”[1][7]. The Bureau of Industry and Security made its detailed guidance public through an official Federal Register notice on October 14, 2026, outlining the specific criteria for assessing U.S. content[1][10]. Prior to this, U.S. Customs and Border Protection issued its initial implementation guidance via Cargo Systems Messaging Service (CSMS) #68855869 on June 5, 2026, providing preliminary instructions to trade stakeholders[5][9].

What we could not confirm

We could not confirm specific economic projections regarding the total value of tariffs expected to be reduced or increased as a direct result of this clarified definition of “U.S. content.” The full scope of industries beyond the RV sector that anticipate direct financial benefits or increased administrative burdens from this guidance remains unconfirmed in the provided records. Details regarding how CBP plans to enforce the provisions for fraud or deliberate misleading of the U.S. government regarding U.S. content were also not specified in the public records available.