Not all US tariffs stack on top of each other — the rules depend on the country of origin and which Section 232 category applies. Understanding how Section 232 (steel, aluminum, auto parts), IEEPA fentanyl tariffs, and reciprocal tariffs interact is essential for accurately calculating your landed cost.
Key takeaways
- Section 232 products are excluded from reciprocal tariffs regardless of country of origin.
- For Canada and Mexico, Section 232 products are also excluded from the IEEPA fentanyl tariff.
- For China (and all other countries), the IEEPA fentanyl tariff still applies on top of Section 232.
- The non-steel/aluminum content of a derivative product is subject to the reciprocal or IEEPA tariff based on origin — it is not automatically exempt.
- Auto parts and automobiles fall under a separate Section 232 (25%) and are excluded from the steel/aluminum Section 232 (50%) even if the HTS code would otherwise qualify.
The three tariff types — a quick orientation
Section 232 tariffs are national-security-based duties imposed on specific product categories: currently steel, aluminum, automobiles, auto parts, and copper. The rates are 50% for steel, aluminum, and copper (25% for the UK); and 25% for autos and auto parts.
IEEPA tariffs are imposed under the International Emergency Economic Powers Act. The most significant is the 20% fentanyl tariff on China and, separately, a tariff on Canada and Mexico (though USMCA-qualifying goods are currently exempt from the Canada/Mexico IEEPA measure).
Reciprocal tariffs are the administration’s trade-balance response, applied by country. Products subject to Section 232 are excluded from the reciprocal tariff — that exclusion applies universally.
How the tariffs actually stack — by country
The key distinction is Canada/Mexico versus the rest of the world, particularly China.
| Country of Origin | Section 232 applies? | IEEPA fentanyl stacks? | Reciprocal tariff stacks? |
|---|---|---|---|
| Canada / Mexico (Section 232 product) | Yes | No — excluded | No — excluded |
| China (Section 232 product) | Yes | Yes — stacks on top | No — excluded |
| All other countries (Section 232 product) | Yes | N/A (no IEEPA fentanyl tariff on most countries) | No — excluded |
In plain English: if your product is subject to Section 232, you will not pay the reciprocal tariff — that is true everywhere. But if your product comes from China, the IEEPA fentanyl tariff (20%) still applies on top of the Section 232 rate. The Section 232 exclusion does not shield Chinese goods from the fentanyl measure.
Why Canada and Mexico are different
The IEEPA fentanyl tariff on Canada and Mexico operates under a separate executive order. Section 232 products from Canada and Mexico are excluded from both the reciprocal tariff and the IEEPA fentanyl tariff — giving those goods a cleaner, single-tariff structure. This is a deliberate policy distinction, not an oversight.
What about the non-Section 232 content in a derivative product?
This is where many importers get caught off guard. When a product is a “derivative” — meaning it contains steel, aluminum, or copper but is not made entirely of those metals — only the metal content is subject to the Section 232 rate. The non-metal portion is not automatically exempt from all tariffs. That remaining value is subject to the reciprocal tariff or IEEPA tariff based on the country of origin, just as it would be for any non-Section 232 product. This requirement to split and declare content separately is now mandatory, not optional. For a detailed look at how this works for steel and aluminum specifically, see our post on Section 232 steel and aluminum at 50%.
Auto parts versus steel/aluminum — an important distinction
If a product is subject to Section 232 as an auto part or automobile, it is assessed at 25% under that provision and is explicitly excluded from the steel/aluminum Section 232 (50%) — even if its HTS code would otherwise qualify for the steel/aluminum tariff. Both auto parts and steel/aluminum products are excluded from the reciprocal tariff. The IEEPA stacking rule above still applies based on country of origin.
What does this mean for China-origin Section 232 goods?
For Chinese goods subject to Section 232 steel or aluminum (50%), the IEEPA fentanyl tariff (20%) stacks on top, creating a combined Section 232 + IEEPA exposure. Add any applicable Section 301 duties and the cumulative rate can reach 70% or higher before accounting for the base duty rate. For a full breakdown of how China tariffs layer together, see our post on what the 55% China tariff really means.
The copper Section 232 follows the same stacking logic — see our guide to the Section 232 copper tariff for the specifics.
Frequently asked questions
Does Section 232 always exclude the reciprocal tariff?
Yes. Products subject to Section 232 (steel, aluminum, copper, autos, auto parts) are excluded from the reciprocal tariff across all countries of origin. The reciprocal tariff and the Section 232 tariff do not stack.
Does Section 232 exclude the IEEPA fentanyl tariff for China?
No. For goods from China, the 20% IEEPA fentanyl tariff applies on top of Section 232. The exclusion from IEEPA for Section 232 products only applies to Canada and Mexico.
If my product is a derivative with both steel and non-steel content, how is it taxed?
The steel/aluminum content is taxed at the Section 232 rate (50%, or 25% for UK). The non-steel/aluminum content is taxed at the applicable reciprocal or IEEPA rate for the country of origin. You must declare the content split at entry and maintain documentation to support the values.
Can a product be subject to both the steel Section 232 (50%) and the auto parts Section 232 (25%)?
No. If a product qualifies as an auto part or automobile under Section 232, the 25% auto parts rate applies and the product is excluded from the steel/aluminum Section 232 (50%). The two provisions don’t stack.
Where can I find the official stacking rules?
The stacking rules are set out in the relevant presidential proclamations published in the Federal Register. Your customs broker can help you identify which proclamations apply to your specific HTS codes and country of origin.
Related reading
- What the 55% China Tariff Really Means (It’s Not What You Think)
- Section 232 Steel & Aluminum at 50%: Derivative Content and Appliances Explained
- Section 232 Copper Tariff: 50% on Copper and Copper Derivatives Explained
- Section 232 changes and how it affects you – importer
- Products exempt from section 232
This article is for general information only and reflects the rules as of its original publication date. Tariff and customs regulations change frequently — consult a licensed customs broker or trade attorney before acting on your specific situation. Contact Simple Forwarding to discuss your shipments.
