The Supreme Court is expected on Tuesday to weigh the availability of a commonly used abortion pill, raising the possibility that it could sharply curtail access to the drug — even in states where abortion access remains legal.

The case means that abortion is once again before the court, less than two years after a conservative majority eliminated the constitutional right to abortion and said it would cede the question of access “to the people and their elected representatives.”

A decision by the justices, expected by late June, could cut off prescriptions by telemedicine and pills sent by mail, two changes in recent years that broadened distribution. It could also have implications for the regulatory authority of the Food and Drug Administration, potentially calling into question the agency’s ability to approve and distribute other drugs.

The current challenge involves mifepristone, a drug approved by the F.D.A. more than two decades ago that is used in nearly two-thirds of abortions in the country. At issue is whether the agency acted appropriately in expanding access to the drug in 2016 and again in 2021.

The court is also expected to consider whether the plaintiffs, a group of anti-abortion doctors and organizations, can show that they will suffer concrete harm if the pill remains widely available. Lawyers call this requirement standing.

The Biden administration had asked the Supreme Court to intervene after a three-judge panel of a federal appeals court favored curbing distribution of the drug. Until the justices decide, access to mifepristone remains unchanged, delaying the potential for abrupt limits on its availability.

Since the decision to overturn Roe v. Wade ended a nationwide right in place for nearly a half-century, abortion pills have increasingly become the focus of political and legal fights.

The case began in November 2022, when a group of anti-abortion doctors and medical organizations sued the F.D.A., asserting that the agency erred when it approved the drug in 2000.

The coalition brought the challenge in Amarillo, a city in the Texas Panhandle where a single federal judge heard all new civil cases. The move all but guaranteed that Judge Matthew J. Kacsmaryk, a Trump appointee openly opposed to abortion, would be assigned the case.

Last March, Judge Kacsmaryk issued a preliminary ruling invalidating approval of the drug and taking the pill off the market.

In August, a three-judge panel of the U.S. Court of Appeals for the Fifth Circuit, one of the country’s most conservative appeals courts, determined that mifepristone should remain legal but imposed significant restrictions on access. Those focused on the F.D.A. decisions in 2016 and 2021.

In a brief to the court, the Biden administration argued that the lower courts had erred in allowing the anti-abortion doctors and organizations to bring the lawsuit “based on speculative and attenuated injuries.” Those rulings, it added, disregarded the “F.D.A.’s scientific judgments by imposing novel requirements that have ‘alarmed the entire pharmaceutical industry.’”

Solicitor General Elizabeth B. Prelogar argued that the plaintiffs offered scant evidence of real injury, including information “related to only seven identified doctors, whose declarations span just a few dozen pages and are often vague or conclusory.”

She also pointed to extensive studies, involving tens of thousands of women, that showed that “serious adverse events that could give rise to the emergency situations” were “extremely rare.”

Lawyers for the anti-abortion doctors and groups contended in court filings that by expanding access to the medication in 2016 and 2021, the F.D.A. had eliminated some “critical safety requirements on its use.”

The rule changes put more pressure on emergency room doctors and obstetrician gynecologists at hospitals to address any complications, the lawyers added.

“When faced with these emergencies,” they wrote, doctors “have no choice but to provide immediate treatment, even though this kind of participation in an elective abortion harms their consciences and injures them in other ways.”