Section 338 Tariffs on Canadian Goods
as_of date on or after
19 August already resolves the 50% on covered Canadian lines.
On 20 July 2026 the President signed three proclamations under Section 338 of the Tariff Act of 1930 (19 U.S.C. 1338), imposing an additional 50 percent ad valorem duty on certain products of Canada. Each proclamation offsets a different Canadian measure: tariffs and quotas on US motor vehicles, provincial restrictions on US alcoholic beverages, and dairy import quotas under Canada's supply management system.
Section 338 lets the President impose duties of up to 50 percent to offset discrimination against US commerce. It has been dormant since the 1930s and 40s, and this is the first time it has been used to actually impose tariffs, so it is a genuinely new authority rather than an extension of the Section 301, 232, or IEEPA programs.
Three details matter for landed-cost math. The duty is in addition to any other duties already applicable, so it stacks on top of the base rate. It applies regardless of whether a good qualifies as USMCA-originating. And it carves out goods already covered by Section 232, alongside energy, potash, fish, certain critical minerals, and articles under the WTO Civil Aircraft Agreement.
Covered products are listed in an annex to each proclamation and range from wine to hockey sticks to cement.
Each tranche has its own Chapter 99 heading:
9903.03.12 for alcoholic beverages and related goods,
9903.03.13 for dairy, and
9903.03.14 for the motor-vehicle tranche, which reaches the
widest basket of the three. USITC has not yet folded these into the published HTS, so the authoritative
scope still lives in the Federal Register annexes. We load it from there rather than wait.
If you import from Canada and want the practical version, read what importers should do before August 19: who is exposed, which goods the Section 232 carve-out spares, and why USMCA origination will not help.
What the API returns today
GET /api/v1/tariffs/resolve returns
section_338 in
additional_measures like any other program, scoped to the
effective date. Query a covered Canadian good with an
as_of before 19 August 2026 and no Section 338 measure comes
back; query it on or after, and the 50 percent duty appears with its Chapter 99 heading attached. The scope
comes from the proclamation annexes themselves, not from a guessed prefix, so every number points at a
heading and a covered subheading you can check against the Federal Register.