IEEPA

Supreme Court Strikes Down IEEPA Tariff Authority

Published March 27, 2026·Updated March 27, 2026

What Changed

Effective February 20, 2026

The Supreme Court issued a ruling on February 20, 2026 striking down the use of IEEPA (International Emergency Economic Powers Act) as authority to impose tariffs. The Court held that IEEPA grants broad economic powers but does not include the authority to impose tariffs — that power is reserved to Congress under Article I, Section 8 of the Constitution. This invalidated the legal basis for tariffs that had been imposed under IEEPA authority in 2025.

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IEEPA-based tariff authorityValid legal authorityStruck down by Supreme Court

Who's Affected

All US importers and the entire US trade policy framework. In the immediate term, the ruling created legal uncertainty about which tariffs could be maintained. The administration responded 4 days later by enacting Section 122 tariffs under separate statutory authority. Importers who paid IEEPA-based tariffs may have grounds for refund claims.

Analysis

Supreme Court Strikes Down IEEPA Tariff Authority (effective 2026-02-20). The Supreme Court issued a ruling on February 20, 2026 striking down the use of IEEPA (International Emergency Economic Powers Act) as authority to impose tariffs. The International Emergency Economic Powers Act (IEEPA) was enacted in 1977 to grant the President broad authority to regulate international commerce in response to a national emergency. The Trump administration used IEEPA as the primary legal authority for its tariff program beginning in 2025, arguing that the US trade deficit constituted a national emergency warranting tariff action. The Supreme Court's February 20, 2026 ruling held that while IEEPA grants broad economic powers, the authority to impose tariffs — a core legislative power — is reserved to Congress under Article I, Section 8. The ruling was a significant constraint on executive trade authority, though the administration moved rapidly to find alternative statutory bases, most notably enacting Section 122 tariffs four days later. The IEEPA ruling has broader implications for trade policy: it establishes constitutional limits on executive tariff authority and could affect how future administrations structure trade actions. Importers who paid IEEPA-based tariffs during 2025 may have legal grounds for refund claims; the CBP has not issued specific guidance on this as of this writing. For current US tariff rates and calculations, the relevant authorities are now Section 122, Section 232, Section 301, and bilateral trade deals — not IEEPA.

Impact & Next Steps

For most importers, the practical effect of the IEEPA ruling is minimal — the Section 122 tariffs enacted 4 days later maintain similar aggregate tariff levels. However, importers who paid tariffs under IEEPA authority in 2025 should consult with a customs attorney about potential refund claims. Ongoing trade litigation may further affect which tariff authorities remain in effect; monitor USTR and CBP bulletins for updates.

Disclaimer: CalcMyTariff.com provides tariff estimates for informational purposes only. Actual duty rates depend on the specific HTS classification of your goods, which requires professional customs brokerage expertise. Rates shown reflect our best interpretation of currently published tariff schedules and may not include all applicable duties, anti-dumping duties, countervailing duties, or special tariffs. Consult a licensed US customs broker for binding determinations. Tariff rates change frequently — verify current rates with CBP or USITC before making import decisions.

Tariff rates from Tax Foundation, USITC, and Penn Wharton Budget Model. Last verified March 27, 2026.