U.S. Section 338 escalates: Sep 15 list changes, Sep 29 import bans for listed Canadian goods

September 11, 2026

On 8 September 2026, the White House issued five Section 338 proclamations. Three exclude listed Canadian products from importation into the United States. Two modify which Canadian products stay under the existing 50% additional duties.

This is the exporter follow-up to the July/August Section 338 50% duty briefs. It is not a how-to for Canadian import clearance, and it is not a blanket ban on Canadian alcohol, dairy, or vehicles. The annex to each proclamation is the product list.

Two clocks that matter

What changes	Effective (Eastern)	What it does
Scope mods to the 50% Section 338 duty lists (additions and removals)	12:01 a.m., 15 Sep 2026 — goods entered for consumption, or withdrawn from warehouse for consumption, on or after	Some Canadian HTS lines move onto or off the 50% duty annexes
Import bans on listed Canadian products	12:01 a.m., 29 Sep 2026 — goods imported on or after	Listed products of Canada are excluded from importation into the U.S.

Source: White House fact sheet (8 Sep 2026) and the operative text of the three exclusion proclamations and two scope-modification proclamations.

Exporter checklist (use this before the next U.S. booking)

1. Match your 8-digit U.S. HTS to the annex — do not trust the sector title.
   The three exclusion proclamations are titled alcoholic beverages, dairy, and motor vehicles. The commercial question is whether your exact HTS line appears in that proclamation’s annex. Titles are political. Annexes are the rule.

2. Treat 15 Sep and 29 Sep as different events (different triggers).

   • From 15 Sep: scope mods apply to goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. ET that day — re-check whether your line was added to or removed from the 50% duty lists under the published alcohol-related and motor-vehicle-related scope modifications (confirm dairy-line duty-list changes against those annexes, the fact sheet, and any CBP Federal Register notice — do not invent a separate dairy scope-mod link).
   • From 29 Sep: if your line is on an exclusion annex, U.S. importation is banned for goods imported on or after that time — not just taxed at 50%. Do not mix this “imported” clock with the 15 Sep entry clock.

3. “Imported but not entered” before 29 Sep stays on the 50% duty path for banned lines.
   Each exclusion proclamation says products that will be subject to the ban and that were imported, but not yet entered for consumption (or withdrawn from warehouse for consumption) prior to 29 Sep 2026, remain subject to the 50% duty from the related July proclamation — they are not treated as banned for that stock. Confirm timing with your U.S. broker against the proclamation language and CBP implementation.

4. USMCA preference does not carve this out.
   The White House fact sheet states these Section 338 tariffs apply to all covered goods regardless of whether a good originates under USMCA, and apply in addition to tariffs imposed under Section 232. The alcohol and motor-vehicle scope-modification proclamations ¶(1) likewise say the modified 50% duties apply in addition to Section 232. The exclusion proclamations exclude annex-listed Canadian products from importation; they state no USMCA carve-out.

5. This is a U.S. import restriction.
   Your Canadian CAD / B13A / CERS filing does not collect the U.S. 50% or administer the ban. Your U.S. customer (or their importer of record) and U.S. Customs and Border Protection do. Tell the U.S. broker both clocks and the annex match before the truck is booked.

6. Watch for CBP / Federal Register HTSUS updates.
   Each proclamation authorizes CBP to implement the ban and to publish any needed HTSUS modifications (including technical annex corrections) in the Federal Register. Do not wait for a CSMS to decide whether you are on the list — use the annex now, then update if CBP publishes a correction.

7. If a ban is later invalidated, the proclamations say the 50% duty snaps back for that import.
   Severability clauses in the exclusion proclamations put the related 50% Section 338 duty back on if the ban (or part of it) is invalidated for that import.

What the fact sheet adds (still not a substitute for the annex)

• Import bans take effect for goods imported on or after 29 Sep 2026; product additions and removals on the 50% lists take effect for goods entered for consumption / withdrawn from warehouse for consumption on or after 15 Sep 2026.
• Examples called out in the fact sheet for the list cleanup: rock salt and cement removed from the Section 338 tariff scope; ATVs and additional dairy products among the replacements/additions. Treat those as fact-sheet illustrations — confirm every SKU against the official annex tables.

FAQ

Is all Canadian beer / cheese / cars banned?
No. Only products listed in the annex to the relevant exclusion proclamation are excluded from importation. Match the 8-digit U.S. HTS.

My goods are already on a boat or in a U.S. warehouse before 29 Sep — are they banned?
If they were imported but not yet entered for consumption (or withdrawn from warehouse for consumption) prior to 29 Sep 2026, the exclusion proclamations say they remain under the 50% duty, not the ban. Confirm entry timing with the U.S. broker.

Does CUSMA / USMCA preference wipe the 50% or the ban?
No. Per the White House fact sheet, Section 338 tariffs apply regardless of USMCA origin and apply in addition to Section 232. The 15 Sep scope-mod proclamations ¶(1) restate that the modified 50% duties apply in addition to Section 232. Annex-listed bans are exclusions from importation (no USMCA carve-out in the operative text).

Who pays / who is refused?
The U.S. importer of record faces CBP. Canadian export paperwork does not clear the U.S. restriction.

Where is the product list?
The annex to each of the three 8 Sep 2026 exclusion proclamations (alcoholic beverages; dairy; motor vehicles), plus the annexes to the two 8 Sep 2026 scope-modification proclamations for the 15 Sep duty-list changes.

Sources (official)

• White House fact sheet, 8 Sep 2026: President Donald J. Trump Responds to Canada’s Retaliation
  https://www.whitehouse.gov/fact-sheets/2026/09/fact-sheet-president-donald-j-trump-responds-to-canadas-retaliation/
• Exclusion proclamation — alcoholic beverages (ban from 29 Sep 2026)
  https://www.whitehouse.gov/presidential-actions/2026/09/excluding-certain-canadian-alcoholic-beverages-from-importation-into-the-united-states-in-response-to-continued-discrimination-against-the-commerce-of-the-united-states-with-respect-to-alcoholic-bever/
• Exclusion proclamation — dairy (ban from 29 Sep 2026)
  https://www.whitehouse.gov/presidential-actions/2026/09/excluding-certain-canadian-products-from-importation-into-the-united-states-in-response-to-continued-discrimination-against-the-commerce-of-the-united-states-with-respect-to-dairy/
• Exclusion proclamation — motor vehicles (ban from 29 Sep 2026)
  https://www.whitehouse.gov/presidential-actions/2026/09/excluding-certain-canadian-products-from-importation-into-the-united-states-in-response-to-continued-discrimination-against-the-commerce-of-the-united-states-with-respect-to-motor-vehicles/
• Scope modification — alcoholic beverages (duty-list changes from 15 Sep 2026)
  https://www.whitehouse.gov/presidential-actions/2026/09/modifying-the-scope-of-products-of-canada-subject-to-the-additional-duties-imposed-to-offset-canadian-discrimination-against-the-commerce-of-the-united-states-with-respect-to-alcoholic-beverages/
• Scope modification — motor vehicles (duty-list changes from 15 Sep 2026)
  https://www.whitehouse.gov/presidential-actions/2026/09/modifying-the-scope-of-products-of-canada-subject-to-the-additional-duties-imposed-to-offset-canadian-discrimination-against-the-united-states-with-respect-to-motor-vehicles/

Related J.W. Smith: Export to USA. Prior importer-side Sep 8 counter-tariff coverage: Monday's counter-tariffs and CAD surtax codes.

J.W. Smith Customs Broker Ltd. handles Canadian export documents and coordinates U.S. clearance with our U.S. agent. Need a line checked against the Sep 15 / Sep 29 annexes before you book? Get an estimate.

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