The Supreme Court on Thursday upheld the Federal Communications Commission’s authority to levy fines through in-house proceedings, ruling 8-1 against wireless carriers AT&T and Verizon in a case that tested the constitutional right to a jury trial in agency enforcement actions.

Chief Justice John Roberts authored the majority opinion. Justice Clarence Thomas, a conservative, was the court’s sole dissenter. The ruling was issued on June 4.

At issue in the legal dispute was whether the FCC’s internal system for imposing financial penalties, known as forfeiture orders, deprived the companies of their right to a jury trial under the U.S. Constitution. The court embraced the Trump administration’s argument that the FCC’s in-house process does not prevent parties from later bringing legal challenges to the agency’s assessments in federal court.

Justice Department lawyers defending the FCC’s system had argued that the agency’s administrative assessments were not binding and that if the government were to bring an enforcement action in court, the companies would be able to make their case before a jury. The companies, for their part, argued that the FCC’s system impermissibly uses in-house proceedings for a process that belongs in court, depriving them of their right to a jury trial. They also said the FCC’s initial assessments inflict reputational harm before the accused have had their day in court.

The case is the latest to test whether a federal agency’s internal enforcement arrangement violates the constitutional right to a jury trial. In 2024, the Supreme Court curbed the power of in-house proceedings at the Securities and Exchange Commission, setting the stage for challenges to similar administrative enforcement systems at other agencies.

The FCC imposed nearly $200 million in total fines on wireless carriers that it said failed to safeguard customer data. The agency fined AT&T $57 million and Verizon nearly $47 million after concluding that the companies had unlawfully sold access to customer location data to third parties without securing user consent. The FCC also fined T-Mobile $80 million and Sprint, which T-Mobile acquired in 2020, $12 million.

Verizon and AT&T paid the fines they were assessed, but also filed legal challenges that eventually led to a split among regional U.S. appellate courts over the lawfulness of the FCC’s in-house procedure for imposing the penalties. The Supreme Court’s ruling resolves that circuit split, affirming the agency’s authority to use its administrative process.