A Section 301 investigation is an inquiry by the Office of the U.S. Trade Representative into a foreign government’s trade practices, authorized by Section 301 of the Trade Act of 1974, that can end in tariffs, suspended trade benefits, or a negotiated settlement. Most people run into these investigations from the importer’s side, through the tariffs they generate. If that is your situation, the practical questions are how the process works, whether you can get your product excluded, whether you can recover duties you have already paid, and when the tariffs expire.
What Section 301 Covers
The statute lets the USTR act against three kinds of foreign government conduct. Unjustifiable conduct violates U.S. rights under international law, typically by breaching a trade agreement or denying American goods national treatment or most-favored-nation status. Unreasonable conduct is unfair or inequitable even when no agreement is technically broken; the statute lists examples including inadequate protection of intellectual property, toleration of anticompetitive practices that block American market access, export targeting, and labor abuses such as forced labor. Discriminatory conduct singles out U.S. goods, services, or investments for worse treatment than others receive.1Office of the Law Revision Counsel. 19 USC 2411 – Actions by United States Trade Representative
The category matters. When the USTR finds unjustifiable conduct that burdens U.S. commerce, the statute requires action to enforce U.S. rights or eliminate the harm. When conduct is unreasonable or discriminatory, the USTR has discretion over whether to respond. Even a mandatory case has exits: the USTR does not have to act if a WTO panel finds no violation, if the foreign country is already taking satisfactory corrective steps, or if retaliation would harm the U.S. economy substantially out of proportion to the benefits.1Office of the Law Revision Counsel. 19 USC 2411 – Actions by United States Trade Representative
How an Investigation Starts
An investigation can begin two ways. Any interested person or business can file a petition identifying the country, the specific policy, and the harm to American commerce, such as lost revenue, decreased market share, or increased costs tied to the foreign practice. The USTR then has 45 days to decide whether to open a formal investigation.2Office of the Law Revision Counsel. 19 USC 2412 – Initiation of Investigations Vague complaints about general unfairness rarely make it through this screening; naming the specific foreign law or regulation is critical.
The USTR can also self-initiate. That path requires notice in the Federal Register and consultation with the relevant private-sector advisory committees. Most of the largest Section 301 actions have started this way, including the 2018 investigation into China’s technology transfer and intellectual property practices and the March 2026 investigations into structural excess manufacturing capacity in multiple economies.3Federal Register. Initiation of Section 301 Investigations: Acts, Policies, and Practices of Certain Economies Relating to Structural Excess Capacity and Production in Manufacturing Sectors
Investigation Timeline
On the day an investigation opens, the USTR must request consultations with the foreign government. If a trade agreement is involved and consultations do not resolve the dispute within 150 days, formal dispute settlement under that agreement must be initiated.4Office of the Law Revision Counsel. 19 USC 2413 – Consultation Upon Initiation of Investigation
Final determinations have hard statutory deadlines:
- Trade agreement disputes: the earlier of 30 days after dispute settlement concludes or 18 months after the investigation begins.
- Other cases: 12 months from initiation.
- Intellectual property cases triggered by a Priority Watch List identification: six months, extendable to nine if the foreign country is making substantial progress.
These are ceilings. The USTR can act sooner, and typically opens a public comment period and holds hearings before publishing the outcome in the Federal Register.5Office of the Law Revision Counsel. 19 USC 2414 – Determinations by the Trade Representative
What the USTR Can Do
When the USTR decides to act, the statute offers a menu: impose additional tariffs with no statutory rate cap, suspend concessions previously granted under a trade agreement, restrict services-sector authorizations, negotiate a binding agreement requiring the country to eliminate the practice or provide compensatory benefits, or withdraw preferential duty-free treatment. The statute directs the USTR to prefer tariffs over other forms of import restriction.1Office of the Law Revision Counsel. 19 USC 2411 – Actions by United States Trade Representative Tariffs are what most affected importers will encounter.
Getting a Product Excluded From the Tariffs
When Section 301 tariffs cover a broad category of imports, individual businesses can ask the USTR to exclude specific products. The request must identify each product by its 10-digit Harmonized Tariff Schedule code, with a physical description detailed enough to distinguish it from similar items that stay covered. Any exclusion granted is defined by that 10-digit classification, not by the wording in the request.6U.S. Customs and Border Protection. GUIDANCE: Section 301 China – Extension of Certain Product Exclusions Covered under Tranche 1
A strong request shows economic impact: that the product cannot be sourced domestically or from a third country not subject to the tariffs, and that the duty causes real financial hardship, such as significantly reduced margins or inability to fulfill contracts. You are also expected to disclose whether the product ties to a broader industrial policy program of the foreign government. The USTR publishes the specific submission procedures through Federal Register notices for each round.7U.S. Customs and Border Protection. Section 301 Trade Remedies Frequently Asked Questions
Claiming Refunds on Duties Already Paid
Exclusions are often retroactive. If you paid Section 301 duties on a product that later received an exclusion, you can recover those duties through U.S. Customs and Border Protection. The route depends on whether your entry has been liquidated:
- Not yet liquidated: file a Post Summary Correction through the Automated Commercial Environment portal. The window closes 300 days after the entry date or 15 days after liquidation, whichever comes first.
- Already liquidated: file a formal protest using CBP Form 19 within 180 days of the liquidation date.8GovInfo. 19 USC 1514 – Protest Against Decisions of Customs Service
Straightforward corrections typically take three to six months. Protests and more complex exclusion situations can run six to twelve months, with payment following an approved refund in another six to eight weeks. Products subject to separate antidumping or countervailing duties, or to Section 232 tariffs on steel and aluminum, generally do not qualify for Section 301 refunds even when an exclusion otherwise covers the product.
The Four-Year Expiration and Continuation Review
Section 301 actions do not last forever by default. Every action expires at the end of four years unless a representative of the domestic industry that benefits from the tariffs files a written continuation request. The USTR must notify affected petitioners and industry representatives by mail at least 60 days before the four-year anniversary. If no one files during that final 60-day window, the tariffs lapse. If someone does, the tariffs continue and the USTR opens a review of whether they are working, whether alternatives would be better, and what the effects on the U.S. economy and consumers have been.9Office of the Law Revision Counsel. 19 USC 2417 – Modification and Termination of Actions
The China tariffs from July and August 2018 went through their first four-year review in 2022 and are in a second round in 2026, with continuation requests due before the respective anniversary dates. If your business relies on the protection, track those windows. If your business is paying the tariffs and betting on expiration, understand that a single industry request keeps them in place.
Challenging a Section 301 Decision in Court
Businesses that believe a tariff or an exclusion denial is unlawful can sue in the U.S. Court of International Trade, which has exclusive jurisdiction over civil actions arising from tariffs and non-revenue import restrictions.10Office of the Law Revision Counsel. 28 USC 1581 – Civil Actions Against the United States and Agencies and Officers Thereof Section 301 litigation has grown, and courts have scrutinized whether the USTR followed all required procedural steps. Judicial review is real but expensive and slow, and it tends to make sense only when the dollar amounts are significant and the legal theory is strong, such as arguments that the USTR exceeded its statutory authority or skipped required consultation and investigation procedures.
Where Things Stand
The largest active program still targets Chinese imports under the 2018 investigation into technology transfer and intellectual property practices. In November 2025, the USTR extended 178 product exclusions from that investigation through November 10, 2026.11United States Trade Representative. USTR Extends Exclusions from China Section 301 Tariffs Related to Forced Technology Transfer Investigation In March 2026, the USTR self-initiated new investigations into structural excess manufacturing capacity across multiple economies, so Section 301 is no longer a China-only tool.3Federal Register. Initiation of Section 301 Investigations: Acts, Policies, and Practices of Certain Economies Relating to Structural Excess Capacity and Production in Manufacturing Sectors If Section 301 tariffs touch your supply chain, watching the Federal Register and USTR announcements is how you catch the exclusion windows, refund deadlines, and continuation reviews that decide what you actually pay.