On April 2, 2026, President Trump issued two presidential proclamations: a proclamation imposing Section 232 tariffs on certain branded pharmaceutical products and associated active pharmaceutical ingredients (APIs) (the Pharmaceuticals Proclamation), and a proclamation modifying the Section 232 steel, aluminum, and copper tariffs (the Metals Proclamation).

For pharmaceutical-related items, these tariffs become effective on July 31, 2026, for certain enumerated pharmaceutical companies,¹ and on September 29, 2026, for all other companies. The updated tariff rates for metals are already in effect.

Below, we highlight the relevant changes stemming from the respective tariff proclamations.

The Pharmaceuticals Proclamation

The new pharmaceutical tariffs follow President Trump’s determination that the U.S.’s heavy reliance on imported APIs threatens to impair both U.S. national security and the broader economy. Specifically, the Pharmaceuticals Proclamation explains that potential global supply chain disruptions could limit Americans’ access to life-saving medications and that a self-sufficient domestic manufacturing and industrial base for pharmaceutical products is essential to “support national defense requirements and maintain public health security during a national emergency or wartime.” Accordingly, President Trump has imposed new tariffs under Section 232 authorities with a stated purpose of encouraging the onshoring of pharmaceutical manufacturing and promoting greater domestic self-sufficiency.

President Trump imposed a 100 percent ad valorem duty rate on imports of certain patented pharmaceuticals and associated APIs, subject to the following exceptions available to products of certain countries and/or companies:

1. A lower ad valorem 20 percent tariff through April 2, 2030, will apply on imports of such products by companies that have plans approved by the Secretary of Commerce to onshore production in the U.S.
2. A functional exemption (0 percent tariff) from these new Section 232 tariffs through January 20, 2029, will apply for products of companies that have executed or are negotiating agreements with the Secretaries of Commerce and of Health and Human Services regarding: i) onshoring plans² for manufacturing (as above) and R&D; AND ii) commitments to sell their pharmaceutical products in the U.S. at negotiated “most favored nation” (MFN) prices, including those companies with agreements recorded in Annex II of the Pharmaceuticals Proclamation.
3. A lower applicable tariff rate will apply to country-specific preferential tariff rates negotiated pursuant to prior trade deals with key U.S. trading partners. Specifically, a lower rate will apply to qualifying products of:
4. The European Union, South Korea, Japan, Switzerland, and Liechtenstein: A 15 percent all-in rate as per their respective implemented trade deals; and
5. UK: An expected, initial 10 percent Section 232 rate to take effect when a previously negotiated pharmaceutical-related agreement is formally implemented. This rate is later contemplated to eventually fall to 0 percent (per current understanding) when agreed to by the U.S. and the UK in a subsequent phase.

The lowest of the above applicable rates will apply for companies meeting the attributes of multiple such exceptions.

The Pharmaceuticals Proclamation also states that there will be no tariffs on imports of:

1. U.S.-origin pharmaceutical products.
2. Generic pharmaceuticals and “their associated ingredients, including biosimilar products.” This exception will be reevaluated in one year.
3. “[D]rugs and associated ingredients, where all approved indications are designated as orphan pursuant to the Orphan Drug Act, 21 U.S.C. 360aa et seq., and its implementing regulations; nuclear medicines; plasma derived therapies; fertility treatments; cell and gene therapies; antibody drug conjugates; medical countermeasures related to chemical, biological, radiological, and nuclear threats.”
4. Other specialty pharmaceutical products to be identified by the Secretary, as well as pharmaceutical products for animal health that: i) “meet an urgent United States health need” (not yet defined) or ii) are “products of a jurisdiction that has a current or forthcoming trade and security framework agreement as referenced in Executive Order 14346 of September 5, 2025 (Modifying the Scope of Reciprocal Tariffs and Establishing Procedures for Implementing Trade and Security Agreements).”
5. Specified products classifiable under HTS codes enumerated on Annex IV to the Pharmaceuticals Proclamation.

All of the foregoing exemptions and preferential rates afforded to specified companies are subject to renegotiation or revocation if the U.S. government determines an agreement is “not being carried out” or is “ineffective.” The Secretary of Commerce is also empowered to charge retroactive or prospective duties “in cases where the executive branch assesses that a company engaged in fraud or deliberately misled the United States Government with respect to onshoring commitment.” Similarly, the Secretary of Commerce is afforded discretion to raise tariffs on any country with lower negotiated rates that fail to fulfill commitments made to the U.S. under those agreements.

The Metals Proclamation

The Metals Proclamation, which is already in effect, updates the calculation method for the prior Section 232 steel, aluminum, and copper tariffs—resolving a complex and ambiguous procedure originally imposed by the Trump Administration in March 2025, wherein the Section 232 tariffs applied only to the value of the subject metal content in covered articles.

Specifically, the updated Section 232 metals tariff will now apply as a specified percentage of the full value of the following articles:

1. A 50 percent tariff for aluminum, steel, or copper commodities enumerated in Annex I-A to the Metals Proclamation (such as steel coils and aluminum sheets), and
2. A 25 percent tariff on specified derivative articles of steel or aluminum enumerated in Annex I-B to the Metals Proclamation. Lower rates apply to products of metals smelted or most recently cast in the UK or the U.S., while higher rates apply to products of metals smelted or most recently cast in Russia.

The Metals Proclamation does not alter or supersede any special rates provided for under prior agreements with the UK, European Union, Japan, or South Korea or under the World Trade Organization Agreement on Trade in Civil Aircraft.

The Bottom Line

The new pharmaceutical and metals tariffs reflect a continuing advancement of the high-tariff agenda. Unlike the reciprocal and fentanyl-related tariffs recently invalidated by the U.S. Supreme Court, these tariff changes rest on more stable legal authorities provided by Section 232 of the Trade Expansion Act of 1962 and may be less susceptible to legal challenges. While other legal authorities (such as Section 301 of the Trade Act of 1974) also may be used to replace the previous tariffs, Section 232 will almost undoubtedly remain part of the broader tariff portfolio for this administration.

However, even though it increases tariff rates, the Metals Proclamation does finally provide importers with much-needed clarity on how to apply the tariffs, resolving longstanding ambiguity and now positioning importers to make necessary changes in their supply chain to achieve certain tariff treatment. In addition, the broad zero percent tariff treatment under the Pharmaceuticals Proclamation—including on generic pharmaceuticals and a broad swath of patented/branded pharmaceuticals for the many companies that have executed onshoring and MFN agreements with the Trump administration—means the new tariffs may serve mostly as an unwielded “stick” intended simply to encourage more companies to commit to U.S. onshoring and more favorable U.S. drug pricing.

The new tariffs also broadly reaffirm that, despite the recent Supreme Court decision, the Trump Administration intends to preserve commitments secured through trade agreements negotiated between the U.S. government and key trading partners and significant multinational pharmaceutical companies, notwithstanding other recent tariff tumults.

Please reach out to Josephine Aiello LeBeau, Anne Seymour, Bryan Poellot, Grace Beck, or another member of Wilson Sonsini’s National Security and Trade practice with questions regarding any of the matters discussed above.

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[1] Listed in Annex III to the Pharmaceuticals Proclamation. The Pharmaceuticals Proclamation includes four annexes: Annex I (HTSUS modifications implementing new tariff structure including HTSUS codes that it applies to); Annex II (a list of 13 key pharmaceutical companies with previously executed agreements); Annex III (a list of the 17 companies on whom the new tariff structure will be effective July 31, 2026); and Annex IV (a list of exempted pharmaceutical and pharmaceutical ingredient products (also exempted from Section 122 tariff).

[2] The Pharmaceuticals Proclamation further directs the Secretary of Commerce and Secretary of Health and Human Services to establish criteria for onshoring plans, including periodic reports and audits. These criteria will be published in the Federal Register.