Trade Remedies

Antidumping Investigation

Also known as: AD Investigation · Dumping Investigation

A formal Commerce Department and USITC investigation to determine whether imports are being dumped and whether they cause material injury — typically lasting 280 to 420 days.

An Antidumping Investigation is the formal procedure conducted by the Commerce Department and the USITC to determine whether to impose antidumping duties on imported merchandise. Procedures are governed by 19 CFR Part 351.

The investigation typically follows this sequence:

  1. Petition filing — A petition is filed on behalf of the domestic industry alleging dumping and injury. Commerce evaluates industry support (at least 25% of domestic production must support and more than 50% of those expressing a view).
  2. Initiation — Commerce initiates within 20 days; USITC has 45 days for a preliminary injury determination.
  3. Preliminary AD determination — Commerce makes a preliminary less-than-fair-value determination roughly 140 days after initiation. If affirmative, suspension of liquidation begins and cash deposits are required at the preliminary rate.
  4. Final AD determination — Commerce makes a final determination roughly 75 days after the preliminary.
  5. Final injury determination — USITC determines material injury within 45 days of the final Commerce determination.
  6. Order — If both agencies make affirmative final findings, an antidumping duty order is issued.

The overall timeline is typically 280–315 days from initiation, with extensions pushing it to 420 days. Commerce calculates an individual dumping margin for each mandatory respondent (usually the two or three largest exporters) and an all-others rate for non-investigated companies. For non-market economies like China, Commerce assigns a separate rate only to exporters that prove independence from government control.

Once an order is in place, administrative reviews recalculate margins annually, and sunset reviews determine whether the order continues every five years.

Built for customs brokers and trade compliance teams

TariffLens classifies your products with cited CBP rulings and GRI reasoning.

Learn more
Related Terms

Antidumping Duty

A duty imposed on imported goods sold in the United States at less than fair value, when those imports cause or threaten material injury to a domestic industry.

Countervailing Duty Investigation

A formal Commerce Department and USITC investigation to determine whether foreign subsidies and resulting imports cause material injury to a U.S. industry.

Dumping Margin

The percentage by which the price of a product sold in the United States is below its "normal value" — the basis for calculating antidumping duties.

All-Others Rate

The weighted-average AD or CVD rate applied to foreign producers that were not individually investigated — typically calculated from the rates of the mandatory respondents.

Separate Rate

An individually calculated AD/CVD rate granted to a producer in a non-market economy that demonstrates independence from government control — alternative to the often-punitive country-wide rate.

Material Injury

Harm to a U.S. industry that is not inconsequential, immaterial, or unimportant — the injury standard the USITC must find before AD or CVD duties can be imposed.
Previous Antidumping Duty Next Assists
Back to all terms