The News

A federal judge in Indiana largely blocked that state’s ban on transition medical care for youth from taking effect on July 1, the latest in a series of courtroom wins for transgender-rights advocates.

Why It Matters: Parents said their children would face serious harm.

The preliminary injunction, issued on Friday by Judge James Patrick Hanlon, allows transgender children in Indiana to continue receiving hormone treatments and puberty blockers while a lawsuit opposing the state’s ban progresses. Gender-transition surgeries for minors, which are rare, remain banned in the state.

The Indiana lawsuit was one of several filed across the country in response to a series of Republican-backed measures banning or severely restricting puberty blockers, hormone treatments and surgeries for transgender youth. The Indiana ban, which passed the Republican-controlled legislature this spring by large margins, was signed into law by Gov. Eric Holcomb, a Republican.

Families of transgender children sued to block the law, saying that it would have put transgender youth at immediate risk of unwanted changes to their bodies, which would have lifelong consequences.

Their lawyers noted that major medical organizations, including the American Academy of Pediatrics, support gender-transition care and have said that bans pose serious mental health risks to young people, infringing not only on their rights but also on the rights of doctors and parents.

Kenneth J. Falk, the legal director for the American Civil Liberties Union of Indiana, said during oral arguments this week that the law was “an attempt by the state to radically interfere” with parental decisions and was “a clear violation of parental rights.”

Background: Transgender-rights supporters have lost in capitols but won in courts.

At least 17 states have passed laws this year banning or severely limiting transition care for minors as Republicans have made restrictions on transgender people a legislative focus.

Still, supporters of transgender rights have had success countering those laws in the courts.

Judge Hanlon, who heard arguments on the injunction on Wednesday in a wood-paneled courtroom in downtown Indianapolis, was appointed to the Federal District Court by President Donald J. Trump.

Federal judges have also blocked or mostly blocked enforcement of transition-care bans passed in prior years in Alabama and Arkansas. In Oklahoma, the state attorney general’s office agreed not to enforce a newly passed ban on transition care until a judge could rule on an injunction request. And in Florida, a judge said this month that the state could not prevent a handful of children whose families sued from continuing their transition treatments.

Like in other states, supporters of the Indiana law said there was not enough evidence to support hormone treatments and puberty blockers for transgender children. They claimed they were seeking to protect young people from making life-altering decisions that they may later regret.

“What the Indiana General Assembly has decided to do is say, ‘We don’t want our children to be part of this grand experiment,’” Thomas M. Fisher, the Indiana solicitor general, told Judge Hanlon.

What’s Next: A trial in Indiana, and more rulings elsewhere.

Judge Hanlon’s ruling is not final: It merely blocks the Indiana law from being enforced until a bench trial can be held on the merits of the lawsuit.

Officials in the Indiana attorney general’s office did not directly say whether they planned to appeal the injunction, but issued a statement saying that the judge’s decision was “not the end of the story” and that the office “will continue to defend the democratically passed laws” of the state.

Lawyers for the plaintiffs said they were pleased with the ruling and were not done fighting the restrictions.

“Our work in Indiana and around the country is far from over — including with this law,” said Chase Strangio, deputy director for transgender justice with the A.C.L.U., who is among the lawyers representing the Indiana plaintiffs.

As the Indiana case progresses, federal and state court judges in other parts of the country are considering similar lawsuits. At least 10 such legal challenges had been filed as of mid-June, with more expected to follow.