Section 338 Tariffs on Canadian Goods
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. The Chapter 99 headings that will carry these duties in the HTS have not been published yet.
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 does not yet return
Section 338 measures, because the HTS subheadings that define their scope do not exist yet. We publish the
rates we can source, and we would rather return a number we can point at a heading for than guess which
Canadian goods fall inside an annex. Once USITC publishes the headings, section_338
will appear in additional_measures like any other program, and
the value is already declared in our OpenAPI schema so it will not break a strict client.