I Supreme Court On Friday it ruled in a 6-3 decision that President Donald Trump exceeded his authority by imposing sweeping tariffs under a federal law meant for national emergencies, a decision that marked a rare defeat for the administration at the high court, which held a 6-3 majority.
The court found that Trump’s use of the International Emergency Economic Powers Act of 1977, known as IEEPA, did not authorize him to impose broad tariffs on goods entering the US.
The Supreme Court said on Friday that the IEEPA does not specify tariffs, but allows the president to “regulate … the importation” of foreign goods after declaring a national emergency to deal with certain “extraordinary and extraordinary” threats.
According to NBC News, this decision does not affect all taxes, leaving in place those imposed on steel and aluminum under different legal authorities. But it breaks down the tariffs into two broad categories: country-by-country tariffs, or “likes,” — which range from 34% in China to the 10% base used in most other countries — and a 25% tariff on certain goods from Canada, China and Mexico, which the administration previously said was aimed at pressuring these countries to stem the flow of fentanyl.
The decision does not prevent Trump from trying to impose taxes under other laws, although these methods come with additional limitations.
The majority concluded that the Constitution “very clearly” provides Congress the authority to impose taxes, including taxes.
Chief Justice John Roberts wrote the majority opinion, and Justices Clarence Thomas, Brett Kavanaugh and Samuel Alito dissented.
“The president asserts extraordinary powers to impose taxes of unlimited amount, duration, and scope. Given the scope, history, and constitutional context of that asserted power, he must show clear congressional authority to exercise it,” Roberts wrote. “Thus, we hold that the IEEPA does not authorize the president to impose tariffs.
“The taxes imposed here may or may not be wise policy. But as a matter of text, history, and precedent, they are clearly legal,” Kavanaugh wrote.
In April 2025, Trump imposed what he called “reconciliation” tariffs on many countries and called it “Independence Day,” declaring the trade deficit a national emergency. Previously, the operations were aimed at Canada, China and Mexico, which authorities have linked to the state of emergency declared for drug trafficking.
The measures have prompted a wave of lawsuits, including challenges brought by nearly a dozen mostly Democratic-led parties.
In May 2025, a federal trade court blocked Trump’s efforts to impose broad tariffs under emergency powers, citing violations of US law and creating economic chaos. In August 2025, the tariffs were ruled unconstitutional by a federal appeals court that also referred to the IEEPA.
Friday’s decision did not decide or specify whether the companies will be reimbursed the billions of dollars already paid. Other businesses, including retailers Costcothey asked lower courts to order the government to return the money, the Associated Press reported.
Since December, the Department of Finance collected more than $133 billion in funds set aside under emergency legislation, according to federal data.
The economic impact of taxes is expected to reach $3 trillion over the next decade, according to estimates from Congressional Budget Office. It is not clear whether the decision will affect the cost of building materials such as wood, steel, aluminum and copper.
