In late February 2026 the Supreme Court ruled that the International Emergency Economic Powers Act did not authorize former President Trump to impose broad import duties. The decision rendered the IEEPA tariffs illegal and clears the way for importers to seek refunds of duties paid under the disallowed measures.

Costco Wholesale filed its complaint in December 2025 with the US Court of International Trade, challenging the legality of the Trump-era duties. The retailer’s suit seeks a full refund of all tariffs it paid and lists the United States government, US Customs and Border Protection and Commissioner Rodney Scott as defendants.

While the ruling opens the door to recover a share of the $133 billion collected from importers, the timeline and procedure for distributing refunds remain undefined. Costco’s ultimate recovery could bolster cash flow and margin outlook if duties are sizable, but legal and administrative hurdles may delay any financial benefit.