The claim
“The US Supreme Court ruled the majority of Trump's 2025 tariffs illegal in February 2026.”
Janet Yellen made the claim on 6 October 2026, in comments reported by Bloomberg Tax about US trade policy and retaliation against tariffs.
Our verdict
True
The claim is accurate. On 20 February 2026, the US Supreme Court ruled that the President could not impose most of the tariffs introduced in 2025, because the law he relied on did not give him that power.
What we found
Several independent sources confirm the ruling and its timing. The Tax Foundation and SCOTUSblog both report that on 20 February 2026 the Supreme Court struck down the tariffs President Trump imposed in 2025. A Congressional Research Service brief published on 23 February 2026 says the same: the Court found the President had no authority under the International Emergency Economic Powers Act (IEEPA) to impose the tariffs in question. The Court's own opinion in Learning Resources, Inc. v. Trump, issued on 20 February 2026, sets out that IEEPA does not authorise these tariffs. Janet Yellen's statement that most of the tariffs were declared illegal matches this. We found no source that contradicts the claim.
The evidence
5 of 6 sources support the claim; none contradict it.
- Background
Bloomberg Tax reports that Janet Yellen said the Supreme Court had declared most of Trump's 2025 tariffs illegal in February 2026.
news.bloombergtax.com· Yellen Says Trump ‘Appalling’ on US Allies, Backs Retaliation - Supports the claim
The Tax Foundation reports that the Supreme Court issued a ruling on 20 February 2026 that struck down the tariffs President Trump imposed in 2025.
taxfoundation.org· Supreme Court Strikes Down President Trump’s Tariffs - Supports the claim
SCOTUSblog reports that on 20 February 2026 the Supreme Court struck down the tariffs imposed by President Trump.
scotusblog.com· Supreme Court strikes down tariffs - Supports the claim
SCOTUSblog's breakdown of the decision says the Court ruled in Learning Resources, Inc. v. Trump that IEEPA does not give the President authority to impose tariffs.
scotusblog.com· A breakdown of the court’s tariff decisionFebruary 20, 2026
- Supports the claim
A Congressional Research Service brief says the Supreme Court ruled on 20 February 2026 that the President lacked authority under IEEPA to impose the tariffs in question.
congress.gov· Supreme Court Rules Against Tariffs Imposed Under the International Emergency Economic Powers Act (IEEPA)February 23, 2026
- Supports the claim
The Supreme Court's slip opinion in Learning Resources, Inc. v. Trump, dated 20 February 2026, addresses whether IEEPA authorises the President to impose the tariffs enacted in 2025.
Supreme Court of the United States· 24-1287 Learning Resources, Inc. v. Trump (02/20/2026)February 20, 2026
What we could not confirm
- The Court's opinion and the summaries we found tie the ruling to tariffs imposed under IEEPA. They do not spell out what share of all 2025 tariffs this covered, so we cannot confirm the exact proportion implied by the word 'majority'.
How we checked
We looked at the Court's own opinion and case documents, a Congressional Research Service brief, and reports from the Tax Foundation and SCOTUSblog, as well as the original report of Yellen's remarks. We reviewed 7 relevant sources.
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