A federal appellate panel said Monday that Alabama’s ban on hormone treatments and puberty blockers for transgender young people could be enforced, the latest in a series of courtroom setbacks for transgender rights advocates.

The three-judge panel from the U.S. Court of Appeals for the 11th Circuit said that a district court judge had erred in partly blocking enforcement of Alabama’s law, which the state’s Republican-controlled Legislature passed last year. All three judges hearing the appeal were nominated to their positions by President Donald J. Trump.

“Absent a constitutional mandate to the contrary, these types of issues are quintessentially the sort that our system of government reserves to legislative, not judicial, action,” Judge Barbara Lagoa wrote in the court’s opinion.

Supporters of transgender rights have looked to the courts to block laws like Alabama’s, which have rapidly become commonplace in conservative states. More than 20 states now have laws banning or severely restricting such care for minors, most of which were passed this year. Several organizations that brought the challenge to the Alabama law criticized the appellate court’s decision on Monday and said in a joint statement that the “case is far from over.”

That statement from the Southern Poverty Law Center, the National Center for Lesbian Rights, the Human Rights Campaign and GLBTQ Legal Advocates & Defenders, added that the laws “serve no purpose other than to prevent parents from obtaining the medical care their children need.”

Steve Marshall, the Alabama attorney general, praised the ruling in a statement as “a significant victory.”

“The 11th Circuit reinforced that the state has the authority to safeguard the physical and psychological well-being of minors, even if the United States attorney general and radical interest groups disapprove,” said Mr. Marshall, a Republican.

L.G.B.T.Q. rights advocates, who say bans on transition treatments are attacks on transgender people that run counter to medical standards, had early success persuading judges to block enforcement of the laws. The first such ban, in Arkansas, was permanently blocked by a federal district judge, and federal judges issued injunctions in several other states.

But conservatives who support the laws, which they say protect children from making life-altering medical decisions they may later regret, have had a sudden turn in their fortunes this summer.

Another federal appellate panel, in the Sixth Circuit, threw out an injunction last month that had temporarily blocked Tennessee’s ban. That decision prompted a federal judge in Kentucky, also in the Sixth Circuit, to suspend an injunction in that state. And in Nebraska, a state judge recently rejected a request to suspend sweeping restrictions.

Judge Lagoa, who was rumored to be in the running for a Supreme Court position in 2020, heard the case with Judge Andrew L. Brasher, an appellate judge, and Judge J.P. Boulee, a federal district judge in Georgia who was named to the panel.

In addition to Alabama, the 11th Circuit includes Florida, where a federal judge said in June that the state could not enforce a similar ban against several families who sued, and Georgia, where a federal judge on Sunday partly blocked enforcement of a ban. It was not immediately clear how the ruling in the Alabama case might affect the lawsuits in those states.

The Alabama lawsuit is in the early stages, with a trial on the merits of the case in district court not expected until next year. But as similar cases pile up nationally, and as judges diverge on the underlying law, it is seen as increasingly likely that the Supreme Court might eventually have the final say on the issue.

In her opinion on Monday, Judge Lagoa drew from the Supreme Court’s reasoning in Dobbs v. Jackson Women’s Health Organization, the case that returned the question of abortion to states.

Judge Lagoa said Dobbs required judges to weigh whether a right is deeply rooted in the country’s history when determining whether a law can be challenged based on the due process clause of the 14th Amendment, as the plaintiffs in the Alabama case sought.

She said the Alabama lawsuit did not pass that test, and that “the use of these medications in general — let alone for children — almost certainly is not ‘deeply rooted’ in our nation’s history and tradition.”

Ernesto Londoño contributed reporting.