How antidumping duties actually get set

A U.S. antidumping duty case starts with one petition and splits into two federal investigations that run on parallel tracks. The Commerce Department calculates whether a duty applies and how large it is, while the U.S. International Trade Commission (USITC) decides separately whether the imports actually hurt a domestic industry.

Who can start a case?

Producers or workers in a U.S. industry file a petition alleging that imports are sold below fair value, or that foreign governments are subsidizing exporters, according to the USITC. The petition goes to Commerce and the USITC at the same time, and Commerce reviews it against statutory criteria before opening an investigation.

Commerce "cannot, by law, consider extra-statutory factors when determining whether or not to initiate an investigation," per the Commerce Department's own guidance on the initiation process. That limits the agency to the legal standard, not policy judgment, at this stage.

What does Commerce actually decide?

Commerce determines whether dumping or subsidizing exists at all, then calculates the margin: the gap between an exporter's home-market price and its U.S. price, or the value of a government subsidy. That calculated rate becomes the duty rate if the case survives both agencies' reviews, per the USITC.

Commerce's preliminary determination is due 140 days after initiation in an antidumping case and 65 days after initiation in a countervailing duty case, according to the Commerce Department's FAQ on investigation initiation. Parties get a 20-day window to dispute exactly which products the order covers.

What does the ITC decide?

The USITC's only question is injury: whether the domestic industry is materially hurt, threatened with harm, or has its establishment materially retarded by the imports in question. A negative finding at either agency kills the case regardless of what the other agency concludes, per the USITC.

Imports are typically treated as too small to matter, a "negligible" volume, if they fall below 3% of total U.S. import volume for that product over the prior 12 months, the USITC says. That threshold rises to 7% when import volumes from several countries under review are combined.

How fast does a case move?

The USITC's preliminary injury vote is due no later than 45 days after a petition is filed, per the USITC and confirmed separately by Commerce's FAQ. If that vote is affirmative, Commerce continues its own review toward a preliminary and then final determination.

If Commerce's preliminary finding comes back negative but its final determination is affirmative, the USITC gets a compressed 75 days to complete its final injury vote instead of the standard 120, per the USITC. In rare cases involving a sudden import surge, Commerce can apply duties retroactively up to 90 days before its preliminary determination is published in the Federal Register, according to the Commerce FAQ.

What happens after duties are imposed?

If both agencies reach affirmative findings, Commerce issues a formal antidumping or countervailing duty order, and U.S. Customs and Border Protection collects the duty at the border on covered imports. Orders don't expire automatically — they're revisited in periodic administrative reviews that can adjust the rate.

A review of aluminum extrusions from China shows how much a rate can move once a case is running. Covering the period from May 1, 2024, through April 30, 2025, Commerce found that 18 companies under review failed to qualify for individual "separate rate" treatment and were instead assigned the China-wide entity rate of 86.01%, according to the Federal Register notice Commerce published on August 17, 2026.

That case illustrates why the rate a company pays isn't fixed at the original order. Separate-rate eligibility, which exporters have to actively demonstrate in each review, determines whether a company gets its own calculated margin or defaults to the often much higher country-wide rate.

Do orders expire?

Not automatically, but they don't run forever either. Commerce must open a "sunset review" of every order no later than 30 days before its five-year anniversary, covering all antidumping and countervailing duty orders issued after January 1, 1995, per the USITC.

Commerce again checks whether dumping or subsidizing would resume if the order lapsed; the USITC again checks whether injury would recur. A full review, triggered when parties show adequate interest in keeping the order, includes hearings and questionnaires and runs up to 360 days; an expedited review, when interest is inadequate, skips the hearing and runs on a 150-day clock, per the USITC. Either agency can extend its deadline by up to 90 days in a complicated case.

The order survives only if the USITC affirmatively finds that revoking it "would be likely to lead to continuation or recurrence of material injury," per the USITC. A negative finding revokes the order and the duty stops.

Where does the legal authority come from?

The process runs through Commerce's Enforcement and Compliance unit, which the agency describes as protecting U.S. businesses "from unfair competition within the United States, resulting from unfair pricing by foreign companies and unfair subsidies to foreign companies by their governments," per Commerce Department's own account of the investigation process. Every step, from initiation through administrative review and sunset review, is published in the Federal Register.

Companies on both sides of a case, domestic petitioners and foreign respondents, can participate throughout: filing comments on scope, submitting questionnaire responses, and requesting administrative reviews once an order is in place. The process gives no side a presumption of the outcome; both agencies have to reach an affirmative finding independently before any duty takes effect.

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