Today President Trump issued a Proclamation modifying the tariff regimes applicable to aluminum, steel, copper, and their derivative articles under Section 232 of the Trade Expansion Act of 1962. The Proclamation significantly restructures the existing Section 232 duties on aluminum, steel, and copper, most notably by applying the tariffs to the full customs value of covered products regardless of the metal content, revising the scope of derivative articles subject to duties, and establishing a tiered tariff framework across different categories of metal products.
The Administration described these changes as intended to simplify tariff administration, address perceived circumvention through downstream products valuation, and strengthen the effectiveness of the Section 232 measures in addressing national security concerns associated with imports of steel, aluminum, and copper.
The modifications outlined in the Proclamation apply to the identified imported articles entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern daylight time on April 6, 2026.
U.S. Customs and Border Protection (“CBP”) is expected to issue implementing guidance through Cargo Systems Messaging Service (“CSMS”) messages addressing entry‑filing and reporting requirements. Despite the changes discussed below, the anti-stacking rules remain in effect.
Adjustments to the Section 232 Tariff Regimes
The existing Section 232 steel and aluminum tariff regimes were originally established by the first Trump Administration in 2018 and have since been modified under subsequent proclamations. In June 2025, Proclamation 10947 increased the steel and aluminum tariff rates and eliminated most remaining exemptions. Most recently, the Trump Administration applied a similar Section 232 framework to copper and certain copper derivative articles in July 2025.
Based on recommendations from the Secretary of Commerce, the President determined that it is necessary and appropriate to further modify the tariffs to apply on a full‑customs‑value basis and to recalibrate the scope and rate structure for covered derivative products.
Application of Section 232 Duties to Full Customs Value
Effective April 6, 2026, the additional duties imposed pursuant to this Proclamation apply to the full customs value of the subject imported product, regardless of the product’s metal content.
This change represents a material shift from prior direction under which Section 232 duties on certain steel and aluminum derivative articles were assessed only upon the value of the steel or aluminum content as reflected on the commercial invoice. Under this new framework, the tariff is applied on the declared import value. Importers will no longer be able to split out steel content value on the commercial invoice for apportionment of the application of the Section 232 tariffs.
Tiered Tariff Structure
The Proclamation establishes a tiered tariff framework with applicable duty rates determined by product type as described by the Annexes to the Proclamation.
50 Percent Rate – Metal Articles and Certain Derivatives (Annex I‑A)
For steel, aluminum, and copper articles, listed in Annex I‑A, the applicable additional duty is 50 percent, applied to the product’s full customs value. This list applies to most HTSUS subheadings in which primary metal products are classified. For these articles, reduced rates are only available as outlined below:
- A 25 percent duty is applicable for United Kingdom products, subject to specified smelting, melting, pouring, and casting requirements; and
- A 10 percent duty is applicable for derivative articles where:
- The aluminum content of which is composed entirely of aluminum that was smelted and cast in the United States,
- The steel content of which is composed entirely of steel that was melted and poured in the United States, or
- The copper content of which is composed entirely of copper that was smelted and cast in the United States.
25 Percent Rate – Certain Derivative Articles (Annex I‑B)
For certain steel, aluminum, and copper derivative articles listed in Annex I‑B, the applicable additional duty is 25 percent, applied to full customs value.
Reduced rates are similarly available as outlined below:
- 15 percent duty is applicable for United Kingdom products, subject to specified smelting, melting, pouring, and casting requirements; and
- Similar to the reduced rate applicable to the merchandise covered by Annex I-A, derivative articles in Annex I-B are subject to a 10 percent duty if the aluminum content of the derivative is composed entirely of aluminum that was smelted and cast in the United States, the steel content of the derivative is composed entirely of steel that was melted and poured in the United States, or the copper content of the derivative is composed entirely of copper that was smelted and cast in the United States.
Products Removed from Scope (Annex II)
Effective April 6, 2026, certain products listed in Annex II are no longer subject to the additional duties imposed under the aluminum and steel Section 232 tariff regimes.
Transitional Treatment for Certain Products (Annex III)
The Proclamation establishes transitional tariff treatment for certain products listed in Annex III through December 31, 2027. During this period:
- For goods with a Column 1 duty rate, or Most Favored Nation (“MFN”) rate, equal to or lower than 15%, the Section 232 duty rate is equivalent to the difference between 15% and the Column 1 duty rate.
- If the Column 1 duty rate is higher than 15%, no additional Section 232 duties on steel, aluminum, or copper would be owed.
Different rates are applied for:
- Derivative articles where the entire aluminum content of is composed entirely of aluminum that was smelted and cast in the United States, or the steel content of which is composed entirely of steel that was melted and poured in the United States; are subject to a 10 percent total duty, inclusive of Column 1 and Section 232 duties; and
- Imports from trading partners with whom the United States does not maintain normal trading relations are subject to a 25 percent total duty
The Proclamation authorizes the Secretary of Commerce and the U.S. Trade Representative to revoke this treatment on a trading‑partner‑specific basis if import levels undermine the objectives of the Section 232 actions.
Beginning January 1, 2028, products covered under this proclamation by Annex III generally will become subject to the duty structure applicable to Annex I‑B products, unless otherwise modified.
Termination of Derivative Inclusion Processes
The Proclamation also terminates the steel, aluminum, and copper derivative inclusion processes established under prior proclamations. Instead, the Secretary of Commerce and the U.S. Trade Representative are authorized to jointly include additional derivative articles within the scope of the Section 232 tariffs on a rolling basis when they determine that imports of such products threaten national security or undermine the effectiveness of the tariff regimes. This provides opportunities for affected U.S. industries to seek additional tariff protections.
Additional Operational Provisions
The Proclamation also provides that:
- Products containing more than one covered metal will be subject to Section 232 duties only once, even if they contain aluminum, steel, and/or copper.
- Goods listed in Annex I‑B or Annex III that do not contain sufficient aluminum, steel, or copper content, as defined in Annex IV, are not subject to Section 232 duties.
- Actions implementing prior Section 232 tariff reductions for civil aircraft and civil aircraft parts under the WTO Agreement on Trade in Civil Aircraft remain in effect.
- Covered articles admitted into a U.S. foreign trade zone on or after April 6, 2026 must be admitted under privileged foreign status, unless eligible for entry under domestic status.
- Manufacturing drawback is available only in limited circumstances for qualifying products meeting specified criteria; otherwise, no drawback is available.
- Existing provisions imposing 200 percent Section 232 duties on Russian aluminum remain in effect.
Looking Ahead
Cassidy Levy Kent’s attorneys, compliance professionals, economists, and licensed customs brokers regularly advise clients on Section 232 tariff developments, derivative article coverage, valuation methodologies, tariff stacking, and compliance strategies affecting the metals, manufacturing, energy, and automotive sectors.
The shift to full‑value tariff assessment and the restructuring of derivative coverage warrant prompt review of product classifications, supply chains, and entry‑filing practices. We expect CBP to issue additional implementation guidance and will continue to provide updates as developments occur.