WASHINGTON — The Supreme Court said Friday evening that the abortion pill mifepristone would remain widely available for now, delaying the potential for an abrupt end to a drug that is used in more than half of abortions in the United States.
The order halts a sweeping ruling by a federal judge in Texas, who had declared the Food and Drug Administration’s approval of the pill more than two decades ago invalid, as an appeal in the U.S. Court of Appeals for the Fifth Circuit moves forward.
It is the second time in a year that the Supreme Court has considered a major effort to sharply curtail access to abortion. In overturning Roe v. Wade in June, a conservative majority said that it was leaving the issue of abortion to elected officials.
Writing for the majority in Dobbs v. Jackson Women’s Health Organization, Justice Samuel A. Alito Jr. said that “the authority to regulate abortion must be returned to the people and their elected representatives.”
But the matter has made its way back to the court, in a case that could have profound implications even for states where abortion is legal, as well as for the F.D.A.’s regulatory authority over other drugs.
If an initial ruling by a federal judge in Texas were to stand, it could pave the way for all sorts of challenges to the agency’s approval of other medications and enable medical providers anywhere to contest government policy that might affect a patient.
The case reached the justices after a swift-moving and tangled fight over the legal status of mifepristone.
In November, an umbrella group of medical associations and a few doctors who oppose abortion filed a lawsuit in the Amarillo division of the federal court system in Texas, guaranteeing that the case would come before a single judge: Matthew J. Kacsmaryk of the U.S. District Court for the Northern District of Texas.
Judge Kacsmaryk, an appointee of President Donald J. Trump, is a longtime opponent of abortion and joined the bench after working at First Liberty Institute, a conservative legal group that focuses on issues of religious liberty.
The group that brought the suit, the Alliance for Hippocratic Medicine, argued that the F.D.A. had improperly approved the pill in 2000 and that mifepristone is unsafe. The agency has strongly disputed those claims, pointing to studies that show that serious complications are rare and that less than 1 percent of patients need hospitalization.
Mifepristone is typically used in combination with a second drug, misoprostol, in the first 12 weeks of pregnancy. More than five million women have used mifepristone to terminate their pregnancies in the United States, and dozens of other countries have approved the drug for use.
This month, Judge Kacsmaryk, in a temporary ruling, declared invalid the F.D.A.’s approval of the drug and gave both parties a week to seek emergency relief before the decision took effect.
Less than an hour later, a federal judge in Washington State, Thomas O. Rice, an appointee of President Barack Obama, issued a contradictory ruling in a separate lawsuit over mifepristone. Judge Rice blocked the F.D.A. from limiting the availability of the pill in 17 states and the District of Columbia, which were parties in that suit.
The competing rulings meant that the matter was almost certainly headed to the Supreme Court.
The F.D.A. immediately appealed Judge Kacsmaryk’s decision, and a divided three-judge panel of the Fifth Circuit upheld the agency’s approval of the drug more than two decades ago, ensuring that mifepristone would remain on the market.
But the panel imposed several barriers to access, siding in part with Judge Kacsmaryk, while the lawsuit moved through the courts. It blocked a series of steps the F.D.A. had taken since 2016 to increase the availability and distribution of the drug, such as allowing it to be sent by mail and to be prescribed by medical providers who are not doctors.
Seeking emergency relief, the Biden administration asked the Supreme Court to intervene while a fast-tracked appeal moved forward.
“If allowed to take effect, the lower courts’ orders would upend the regulatory regime for mifepristone, with sweeping consequences for the pharmaceutical industry, women who need access to the drug and F.D.A.’s ability to implement its statutory authority,” the government’s brief said.
Adam Liptak contributed reporting.
