最高法院结束了对行政部门修改301条款关税的权力的质疑

June 2026 On June 15, 2026, the US Supreme Court denied the petition for the writ ofcertiorarifiled byHMTX Industries, LLC to challenge the Office of the US Trade Representative’s (USTR) authority Most immediately, the US Supreme Court’s denial of the petition marks the end of the efforts from importers to force USTR torollback its List 3 and List 4A modifications of the initial Section 301 tariffs levied on China after the conclusion of its Section 301 Background of the Section 301 tariff litigation •In August 2017, during President Donald Trump’s first term, USTR launched a Section 301 investigation into China’s tradepractices that concluded in March 2018, and resulted in the imposition of 25% tariffs on a variety of goods included in List 1 •Following Chinese retaliation in response to the initial Section 301 tariffs, USTR announced modifications to the initial Section301 tariffs via release of List 3 and List 4A effective in 2018 and 2019, respectively. List 3 and List 4A included new tariffs on a •The imposition of the additional tariffs led thousands of importers to file lawsuits at the Court of International Trade (CIT) in2020 to challenge (1) the use of Section 301 in response to China’s retaliatory tariffs, and (2) USTR’s modification of the initial •After a procedural victory for the petitioners in 2022, the CIT ruled in favor of the government in 2023, upholding the List 3and List 4A tariffs as lawful exercises of authority under Section 301. •In 2025, importers escalated the litigation by filing an appeal to the US Court of Appeals for the Federal Circuit. The petitionersfailed to convince the court that USTR’s authority to modify Section 301 tariffs pursuant to Section 307 is limited to modestadjustments, rather than entirely new tariffs. The US Court of Appeals for the Federal Circuit upheld List 3 and List 4A tariffs in Impact on importers With the US Supreme Court’s denial to hear the petitioner’s case, the appellate path for importers to challenge these Section 301tariffs is exhausted and the decision by the US Court of Appeals for the Federal Circuit stands. As a result, the Section 301 tariffs All consolidated cases filed by thousands of importers after HMTX Industries, LLC will either be dismissed or decided inaccordance with the precedent set by the US Court of Appeals for the Federal Circuit. Importers can expect that with the courts’ blessing of the government’s broad interpretation of the modification authority underSection 307, USTR may decide to impose additional tariffs with respect to this Section 301 investigation and others in the future. Next steps In the short-term, importers should focus on optimizing operational and compliance strategies, such as supply chain reviewsand adjustments, as well as tariff mitigation via robust tariff classification and country of origin analyses of their products. Looking ahead, importers can participate in USTR’s periodic reviews of imposed Section 301 tariffs. By statute, the Section301 tariffs expire after four years unless an interested party requests their continuation. At that time, importers can submitcomments to advocate for their termination. Outside of the statutory timeline, USTR may launch periodic reviews in responseongoing or new trade issues and hold public hearings where importers can further argue that the Section 301 tariffs shouldbe abandoned. Additionally, at USTR’s discretion, importers can have opportunities to apply for product specific exclusions Contacts Ludmilla KasulkePartner, Washington DCT +1 202 457 5125ludmilla.kasulke@squirepb.com Jeremy W. DutraPartner, Washington DCT +1 202 626 6237jeremy.dutra@squirepb.com John D KarellasAssociate, Washington DCT +1 202 626 6849john.karellas@squirepb.com