Section 232 Tariffs Expand to Medium and Heavy-Duty Vehicles, Parts, and Buses

On Oct. 17, President Donald J. Trump issued a proclamation under Section 232 of the Trade Expansion Act of 1962 imposing sweeping new tariffs on medium- and heavy-duty trucks, truck parts, and buses, marking the first time that the United States has applied Section 232 measures to an entire vehicle class outside the passenger car segment.

The new tariffs, 25 percent on trucks and key truck parts and 10 percent on buses, will take effect on Nov. 1, and will apply according to the rules on tariff stacking.

The New Tariff Framework

Under the proclamation, the United States will impose:

• A 25% ad valorem duty on imports of medium- and heavy-duty trucks and truck parts (including engines, transmissions, tires, and chassis).
• A 10% ad valorem duty on buses, including school buses, transit buses, and motor coaches.

These tariffs apply to goods entered for consumption on or after 12:01 a.m. EDT on Nov. 1, under newly created HTSUS Subchapter 9903.74, established in new Subchapter III of Chapter 99 and defined by U.S. Note 38.

Tariff Stacking and Carveouts

Tariff stacking occurs when multiple tariffs apply to an imported item. Rules about tariff stacking govern which tariffs are applied together.

Products subject to the new truck and bus tariffs will not be subject to overlapping Section 232 tariffs on steel, aluminum, copper, automobiles, or lumber, nor to reciprocal tariffs imposed on Canada, Mexico, Brazil, or India. However, other duties continue to apply, such as the general duty rate, section 301 tariffs, and antidumping or countervailing duties among others.

The tariff stacking and drawback rules for trucks and buses mirror those under the existing auto proclamation, limiting refund claims and restricting multiple offsets on the same import transaction.

USMCA and “Non-U.S. Content” Valuation

For USMCA-qualifying imports of medium- and heavy-duty vehicles (MHDVs), , except for buses and other vehicles classified in HTSUS heading 8702, the 25 percent duty applies only to the non-U.S. content of the vehicle, with Commerce expected to define “United States content” as value derived from domestic production activity.

For USMCA-qualifying imports of individual vehicle parts (MHDVPs), the 25 percent duty will not apply until the Secretary of Commerce, in consultation with the CBP, establishes a comparable valuation process for non-U.S. content. Knock-down kits and equivalent parts compilations remain fully dutiable regardless of origin.

Import Adjustment Offsets

To spur domestic assembly, the proclamation creates an import-adjustment offset for manufacturers of trucks and engines assembled in the United States between Nov. 1, 2025, and Oct. 31, 2030. The offset equals 3.75 percent of the aggregate value of U.S.-assembled vehicles, reflecting a 25 percent tariff on parts representing roughly 15 percent of total vehicle value. Commerce may suspend the program if offsets undermine national-security goals.

Recognizing overlapping supply chains, the proclamation also amends and extends the automobile Section 232 program through April 30, 2030, ensuring parity across the truck and auto sectors.

The Expanding Reach of Section 232

Since 2018, Section 232 has evolved from a narrow national security safeguard for metals into a broad industrial planning tool. What began with steel and aluminum has now reached copper, automobiles, and lumber, and even derivative consumer products far outside the traditional industrial sphere.

Commerce’s latest investigation found that imports of MHDVs, MHDVPs, and buses threaten to impair the national security of the United States. MHDVs were deemed essential to military readiness and emergency response, with imports accounting for 43 percent of total U.S. truck sales and 50 percent of Class 8 trucks—the heaviest duty category. The Administration concluded that offshoring of truck and parts production creates vulnerabilities in defense logistics and supply resilience.

Rationale and National Security Justification

The Administration’s justification blends defense logistics, industrial resilience, and macroeconomic considerations. Trucks and buses are described as indispensable to military troop movements, disaster response, and the continuity of American critical infrastructure, moving over 70 percent of the Nation’s freight by weight, including essential goods such as food, fuel, and medical supplies.

Commerce also cited the erosion of domestic parts manufacturing particularly in engines, transmissions, and castings as a source of vulnerability. The Administration concluded that “only factories here, on American soil, subject to American law, can provide that kind of reliable capacity.”

Policy Context: From Autos to Industrial Planning

The Oct. 17 proclamation fits within a broader pattern of Section 232’s transformation into a structural policy instrument. The Administration now uses Section 232 not just to shield individual sectors but to link tariff relief, domestic production requirements, and cross-sector coordination.

The truck proclamation directly references the March 2025 auto tariffs and the May 2025 copper tariffs, signaling a unified national-security framework spanning the U.S. vehicle, metals, and energy supply chains. It also authorizes Commerce to expand coverage to additional truck parts through a formal inclusion process, similar to the derivative product mechanism introduced for steel and aluminum earlier this year.

Together, these measures indicate an emerging “232 ecosystem” that is increasingly dynamic, iterative, and integrated, blurring the line between trade remedy and industrial strategy.

For policymakers, this move underscores the Administration’s intent to make Section 232 not just a defensive measure but a structural lever of industrial planning. For businesses, it shows how swiftly the scope of Section 232 can expand into parallel industries, and how easily derivative products can impact broad sectors of the supply chain.

Practical Implications for Importers and Manufacturers

• Scope of Coverage: The new duties apply to nearly all MHDVs classified under HTSUS headings 8701.21–8709.19 and to an extensive list of components across HTSUS Chapters 40, 73, 84, 85, and 87 (see Annex I of the Proclamation).
• Compliance Timeline: Duties apply to entries made on or after Nov. 1, 2025. Commerce and CBP are expected to issue implementing guidance in the coming weeks.
• Documentation: Importers seeking USMCA treatment must document U.S. content value to CBP’s satisfaction.
• Offset Applications: U.S.-based manufacturers should begin gathering assembly data for offset applications under the 2025–2030 accrual period.
• Exclusion and Inclusion Processes: The Secretary of Commerce may establish a process to review additions of specific medium- and heavy-duty vehicle parts based on monitoring and stakeholder input.
• Stacking & Drawback Restrictions: Multiple offset or drawback claims on overlapping tariff programs will be restricted under HTSUS 9903.74.

Contact Clark Hill

If you have questions about how these may affect your imports or would like assistance evaluating product coverage, please reach out to any of the contacts below or another member of Clark Hill’s International Trade Business Unit.

• Mark Ludwikowski (mludwikowski@clarkhill.com; 202-640-6680)
• Kevin Williams (kwilliams@clarkhill.com; 312-985-5907)
• Aristeo Lopez (alopez@clarkhill.com; 202-552-2366)
• Kelsey Christensen (kchristensen@clarkhill.com; 202-640-6670)
• Laura M. Quesada (Lquesada@clarkhill.com; 202-240-0170)

 

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