Section 338 Tariffs on Canada: What Procurement Teams Must Do Before August 19, 2026

Most tariff actions since 2025 have run through Section 301 or Section 232. Section 338 is different — it has not been used at scale in nearly a century, and its structure gives the administration authority that neither of those statutes carries. For procurement leaders, understanding why this specific statute was chosen matters almost as much as knowing the tariff rate, because it determines how long the duty is likely to last and whether a negotiated carve-out is realistic.

What is Section 338 and why did the U.S. use it against Canada?

Section 338 of the Tariff Act of 1930 lets the president impose duties of up to 50% on goods from a country found to discriminate against U.S. commerce, without the lengthy investigation process Section 301 requires. On July 20, 2026, the administration issued three Presidential Proclamations invoking Section 338 against Canada for the first time, citing discriminatory treatment of U.S. exporters.

Because Section 338 authority is triggered by a discrimination finding rather than an economic-injury investigation, it can be deployed faster than a Section 301 case — but it is also more legally novel, meaning industry challenges are more likely and the rules around exclusions are still being clarified through follow-on guidance from Customs and Border Protection.

Which products face the new 50% tariff?

The proclamations cover a defined list of Canadian-origin product categories rather than all Canadian imports. Confirmed categories include dairy products, alcoholic beverages, motor vehicles, consumer goods, industrial materials, machinery, telecommunications equipment, furniture and sporting goods.

According to the Office of the U.S. Trade Representative, the covered categories represent close to $20 billion in annual U.S. imports from Canada. Procurement and trade-compliance teams should not assume a product is exempt simply because it falls outside the headline categories of dairy and motor vehicles — several law firm trade advisories have flagged industrial inputs and telecom hardware as easy to overlook during a first-pass exposure review.

When do the tariffs take effect and is there a grace period?

The additional 50% duty applies to covered goods entered for consumption, or withdrawn from warehouse for consumption, on or after August 19, 2026, at 12:01 a.m. EDT. There is no announced grace period or phase-in window for shipments already in transit, which is a shorter runway than the 60- to 90-day windows procurement teams have typically had with Section 301 actions.

Any covered goods that clear customs before that timestamp remain subject to the prior duty rate. Teams with flexibility on shipment timing should evaluate whether accelerating already-planned Canadian orders ahead of August 19 is commercially worthwhile, while weighing the working-capital cost of pulling inventory forward.

Does USMCA protect Canadian-origin goods from this tariff?

No. Covered goods remain subject to the Section 338 duty even when they qualify for preferential USMCA treatment. The additional duty is layered on top of any other applicable duties, taxes, fees and trade remedies, unless a specific product exclusion applies.

This is the detail catching the most procurement teams off guard. Sourcing strategies built over the past several years around USMCA-qualifying content — including supplier requalification projects and regional-value-content calculations — do not shield a covered product from this specific tariff. USMCA compliance and Section 338 exposure now have to be tracked as two separate, additive cost lines.

How should procurement teams assess their exposure?

Exposure assessment starts with a full HTS-code inventory of active Canadian suppliers, cross-checked line by line against the Section 338 annex, not just the headline product categories named in press coverage.

A practical sequence: first, pull 12 months of import data by HTS code and supplier; second, flag every line item that falls inside a covered category, including components and sub-assemblies sourced indirectly through Canadian intermediaries; third, model landed cost at the new 50% add-on rate against current contract pricing; fourth, rank exposure by both dollar volume and switching difficulty, since a small-dollar line with no alternate supplier can be a bigger operational risk than a large-dollar line with three qualified backups.

What sourcing and contract strategies can offset the cost?

The main levers are supplier diversification, tariff-engineering review of product classification, and contract language that shares or caps tariff-driven cost increases rather than absorbing them silently.

Trade advisories published since the proclamation recommend embedding explicit tariff-adjustment clauses in new and renewing supply contracts, rather than relying on general force-majeure or price-escalation language that was not written with country-specific tariff actions in mind. Where switching costs are high, some teams are evaluating bonded warehouses or foreign-trade-zone processing to defer duty payment until goods actually enter U.S. commerce, and requesting first-sale valuation reviews to ensure duties are calculated on the correct transaction value rather than an inflated downstream price.

Nearshoring and reshoring evaluations that were already underway in response to earlier 2025-2026 tariff actions on China and Brazil are being extended to cover Canadian-origin categories as well, particularly for industrial materials and machinery where qualified alternate suppliers exist in Mexico or domestically.

Are exclusions or refunds available?

Product-specific exclusions are referenced in the proclamations but the process for requesting one has not been fully detailed in public guidance as of early August 2026, and companies should expect the exclusion-request mechanism to be published separately by USTR or Customs and Border Protection.

Until that mechanism is published, the safest posture is to document exposure, retain broker and customs-counsel support, and avoid assuming any category will be excluded before it is confirmed in writing. Companies that petitioned successfully for exclusions under earlier Section 301 China actions report that early, well-documented filings — with clear evidence of supply unavailability outside Canada — fared better than late or generic requests.

How long will the Section 338 tariffs remain in place?

Unlike Section 122 of the Trade Act of 1974, which caps action at 150 days, Section 338 carries no fixed expiration date. The tariffs remain in effect indefinitely unless the president acts to modify or terminate them.

That open-ended structure is the single biggest planning variable for procurement teams. Contract negotiations, supplier requalification timelines and capital decisions on nearshoring should be built around the tariff persisting for multiple years, with a modification or rollback treated as a favorable surprise rather than a base-case assumption.

Frequently Asked Questions

Does the Section 338 tariff apply to goods already in transit on August 19, 2026?
Goods entered for consumption before 12:01 a.m. EDT on August 19, 2026 remain subject to the prior duty rate; goods entered on or after that timestamp are subject to the additional 50% duty, regardless of shipment date.

Can a USMCA certificate of origin exempt a product from the new tariff?
No. Section 338 duties apply on top of existing duties even for goods that qualify for preferential USMCA treatment, unless a specific product exclusion is granted.

Which product categories are covered by the new 50% duty?
Confirmed categories include dairy products, alcoholic beverages, motor vehicles, consumer goods, industrial materials, machinery, telecommunications equipment, furniture and sporting goods, representing close to $20 billion in annual U.S. imports from Canada.

Is there a scheduled end date for the Section 338 tariffs on Canada?
No. Unlike time-limited statutes such as Section 122 of the Trade Act of 1974, Section 338 has no fixed expiration and remains in force until the president modifies or terminates it.

What should procurement teams do first?
Run an HTS-code exposure audit against the Section 338 annex, model landed cost at the new rate, and prioritize contract and sourcing mitigation for the highest-exposure, hardest-to-switch supplier relationships before August 19, 2026.

Last updated: August 5, 2026. This article summarizes publicly available trade-advisory guidance and does not constitute legal or customs-compliance advice; procurement and trade-compliance teams should confirm classification and exclusion questions with customs counsel.

Written by the Kurums Procurement Desk, covering sourcing, supplier management and trade-compliance strategy for corporate procurement teams. Related reading: Tariff Refunds and Cocoa Price Swings: Inside Procurement’s 2026 Sourcing Diversification Playbook, Beneficiary: Payment-Party Identity, Change Control and Release Authority, and the Procurement Department Hub for more sourcing and cost-reduction playbooks.