The below was taken in part from Miller & Chevalier:

On April 29th, 2025, President Donald Trump issued an Executive Order (EO) “Addressing Certain Tariffs on Imported Articles – The White House,” clarifying that each of the tariffs he has imposed pursuant to the International Emergency Economic Powers Act (IEEPA) and Section 232 of the Trade Expansion Act of 1962, serve separate and distinct policy purposes, but should “not all have a cumulative effect (or ‘stack’ on top of one another)” to the extent that they apply to the same imported article. 

Stating that the rate of duty resulting from stacking “exceeds what is necessary to achieve the intended policy goals,” the EO sets out the procedure for determining which tariffs will apply to an article when that article is subject to more than one tariff action.

• Articles subject to Section 232 tariffs on automobiles and auto parts will not also be subject to Section 232 tariffs of 25% on steel or aluminum. IEEPA tariffs will be on Canadian and Mexican goods ONLY. They will also not be subject to the reciprocal duties.

Articles subject to IEEPA tariffs on Canadian and Mexican goods will not also be subject to Section 232 tariffs on steel and aluminum.

Articles subject to Section 232 steel tariffs may still “stack” with Section 232 aluminum tariffs and vice versa, potentially leading to 50% tariffs on items that qualify for both steel and aluminum tariffs. (Not pertaining to auto parts/automobile.)

• The “reciprocal” tariffs announced on April 2nd, 2025 are not stackable with any of the above tariffs. (Country Specific currently +10% excluding China)
• Importantly, IEEPA tariffs on Chinese goods related to synthetic opioids and Section 301 tariffs remain stackable with other tariffs. Antidumping and countervailing duties are also stackable with all tariffs. (Please see previous Customer Advisories for guidance.)

The EO applies retroactively to all entries made on or after March 4th, 2025, and importers may request refunds for overpaid duties. The EO clarifies that “refunds will be processed pursuant to applicable laws and US Customs and Border Protection’s (CBP) standard procedures for such refunds.”

CBP will publish refund procedures and any necessary updates to the Harmonized Tariff Schedule of the United States (HTSUS) in a Federal Register Notice no later than May 16th, 2025. Filers should refrain from requesting refunds until refund procedures are announced in the Federal Register Notice. Please note that CBP’s Guidance has not yet been issued on this announcement.

RIM will continue to closely monitor this evolving situation and provide updates as necessary. Please reach out to your RIM representative should you have any further questions.