Lower courts had blocked the policy, saying it was not supported by evidence and violated equal protection principles.
The Supreme Court ruled on Tuesday that the Trump administration may start enforcing a ban on transgender troops serving in the military that had been blocked by lower courts.
The ruling was brief, unsigned and gave no reasons, which is typical when the justices act on emergency applications. It will remain in place while challenges to the ban move forward.
The court’s three liberal members — Justices Sonia Sotomayor, Elena Kagan and Ketanji Brown Jackson — noted dissents but provided no reasoning.
The case concerns an executive order issued on the first day of President Trump’s second term. It revoked an order from President Joseph R. Biden Jr. that had let transgender service members serve openly.
A week later, Mr. Trump issued a second order saying that “adoption of a gender identity inconsistent with an individual’s sex conflicts with a soldier’s commitment to an honorable, truthful and disciplined lifestyle.”
The Defense Department implemented Mr. Trump’s order in February, issuing a new policy requiring transgender troops to be forced out of the military.
