On June 15, 2026, the U.S. Supreme Court denied the petition for a writ of certiorari in HMTX Industries, LLC v. United States (No. 25-1012), bringing the long-running challenge to the 2018-2019 Section 301 tariffs on Chinese-origin goods to a close. The denial leaves intact the Federal Circuit's September 25, 2025 decision upholding the legality of the List 3 and List 4A duties and effectively forecloses refund claims for the thousands of importers who paid those duties.
Background
The litigation, consolidated in the Court of International Trade as In re Section 301 Cases, challenged the U.S. Trade Representative's authority to expand the original Section 301 action against China. USTR initially imposed duties on roughly $50 billion in Chinese goods, then relied on its modification authority under Section 307 of the Trade Act of 1974 to add Lists 3 and 4A, covering an additional $320 billion or more in imports. Importers argued that an expansion of that magnitude exceeded the power to "modify" an existing action and that USTR failed to comply with the Administrative Procedure Act.
The CIT rejected the substantive challenges, and on September 25, 2025 the Federal Circuit affirmed, holding that Section 307(a)(1)(C) independently authorized the List 3 and 4A tariffs and that USTR satisfied APA procedures. The court of appeals also rejected the importers' nondelegation and major-questions arguments.
The Question Presented
The cert petition asked the Court to decide whether USTR's streamlined "modify" authority under Section 307 confers essentially unlimited power to expand the scope of an initial Section 301 action, as reflected in the roughly tenfold expansion at issue. After several extensions, the petition was filed February 20, 2026, the government's opposition followed, and the Court denied review on June 15, 2026 without comment.
What the Denial Means
A denial of certiorari is not a ruling on the merits, but its practical effect here is significant. With the Federal Circuit's judgment now final and conclusive, the List 3 and 4A Section 301 duties remain valid and importers who paid them are not entitled to refunds. This stands in contrast to the IEEPA "reciprocal" tariffs, which the Supreme Court struck down in February 2026 in the Learning Resources matter. The Section 301 tariffs on Chinese goods were never affected by that decision and continue in force.