The federal government on Thursday permanently lifted a major restriction on access to abortion pills. It will allow patients to receive the medication by mail instead of requiring them to obtain the pills in person from specially certified health providers.

The decision, by the Food and Drug Administration, comes as the Supreme Court is considering whether to roll back abortion rights or even overturn its landmark 1973 decision in Roe v. Wade that made abortion legal nationwide.

The F.D.A.’s action means that medication abortion, an increasingly common method authorized in the United States for pregnancies up to 10 weeks’ gestation, will become more available to women who find it difficult to travel to an abortion provider or prefer to terminate a pregnancy in their homes. It allows patients to have a telemedicine appointment with a provider who can prescribe abortion pills and send them to the patient by mail.

Earlier this year, for the duration of the pandemic, the F.D.A. temporarily lifted the in-person requirement on mifepristone, the first of two drugs used to end a pregnancy. The decision to make this change permanent is likely to deepen the already polarizing divisions between conservative and liberal states on abortion. In 19 states, mostly in the South and the Midwest, telemedicine visits for medication abortion are banned, and these and other conservative states can be expected to pass other laws to further curtail access to abortion pills.

Yet other states, like California and New York, which have taken steps in recent years to further solidify access to abortion, are expected to increase the availability of the method and provide opportunities for women in states with restrictions to obtain abortion pills by traveling to a state that allows them.

“It’s really significant,” said Mary Ziegler, a law professor at Florida State University. “Telehealth abortions are much easier for both providers and patients, and even in states that want to do it, there have been limits on how available it is.”

Groups that want to outlaw abortion issued strong statements against the decision.

“The Biden administration today moved to weaken longstanding federal safety regulations against mail-order abortion drugs designed to protect women from serious health risks and potential abuse,” said a statement from the group Susan B. Anthony List. “The Biden administration policy allows for dangerous at-home, do-it-yourself abortions without necessary medical oversight.”

The F.D.A. did not issue a formal statement on Thursday, but it updated a web page to reflect the decision and sent letters about the change to the two companies that make mifepristone and to medical groups that had sued over the requirement.

“The agency conducted a comprehensive review of the published literature, relevant safety and adverse event data, and information provided by advocacy groups, individuals and the applicants to reach this decision,” an F.D.A. spokeswoman said.

The F.D.A. did not ease two other elements of its restrictions on mifepristone, which fall under a program called Risk Evaluation and Mitigation Strategy. One restriction requires patients to sign an agreement acknowledging that their provider has informed them about the drug. The other requires it to be prescribed by a specially certified health provider.

“F.D.A. has determined that certain restrictions continue to be necessary to ensure the safe use of the drug,” the spokeswoman said.

The agency did say Thursday that pharmacies could begin dispensing mifepristone if they became certified by the drug’s manufacturers and if they received the prescription from a certified health provider. Reproductive health experts said they expected further details about pharmacies’ role to be worked out in the coming weeks.

So far this year, presumably in anticipation of such a decision, six states banned the mailing of pills, seven states passed laws requiring pills to be obtained in person from a provider, and four states passed laws to set the limit on medication abortion at earlier than 10 weeks’ gestation, said Elizabeth Nash, the interim associate director of state issues for the Guttmacher Institute, a research organization that supports abortion rights.

Susan B. Anthony List said in its statement that next year, at least seven additional states were likely to enact laws restricting the method.

The current practice is that women who live in states that don’t allow telemedicine for abortion must travel to a state that does — although they don’t have to visit a clinic. They may be in any location within that state for their telehealth visit, even a car, and may receive the pills at any address in the state.

But legal experts said they expected supporters of abortion rights to try to find ways to make the pills available without requiring a patient to travel, including possibly filing legal challenges to state laws banning telemedicine for abortion.

“There’s going to be plenty of people who try to use them in states where they’re illegal without traveling out of state, legal ramifications aside,” said Professor Ziegler. She said such efforts might include clearinghouses that would try to allow “fudging where people’s addresses are to receive it” and a “black market” that might emerge.

In data released last month by the Centers for Disease Control and Prevention, 42 percent of all abortions — and 54 percent of abortions before 10 weeks — occurred with medication in 2019, the most recent year for which C.D.C. data is available. (The report represents most of the country, but does not include data from California, Maryland and New Hampshire.)

In 2020, in some states, including Indiana, Kansas and Minnesota, the method accounted for a majority of abortions, according to state health department reports.

The C.D.C. also reported that 79 percent of all abortions occurred before 10 weeks’ gestation, suggesting that there are many more women who might choose abortion pills over an in-clinic procedure if they could.

Mifepristone was approved in the United States in 2000. The F.D.A. imposed restrictions on the drug, which blocks progesterone, a hormone necessary for pregnancy to develop. The rules allowed patients to take mifepristone in their homes or anywhere they chose once they got it from the certified provider, making it the only drug that the agency required to be obtained in person from a medical provider but that did not need to be taken in the presence of a provider, medical experts say.

The second medication, misoprostol, which causes contractions similar to a miscarriage and is taken up to 48 hours later, has long been available with a typical prescription.

Mainstream medical organizations and abortion rights groups have long urged the government to ease restrictions on mifepristone, citing data indicating that mifepristone is effective and safe, including when dispensed by mail.

For example, a research program that the F.D.A. allowed to provide telemedicine consultations and send pills by mail reported that 95 percent of the 1,157 abortions that occurred through the program between May 2016 and September 2020 were completed without requiring any follow-up procedure. Patients made 70 visits to emergency rooms or urgent care centers, with 10 instances of serious complications, the study reported.

In 2020, medical groups filed a lawsuit asking that the in-person dispensing requirement be lifted because the pandemic meant that patients faced greater risk of being infected with the coronavirus if they needed to visit clinics to obtain abortion pills. A judge granted the request that summer, but, after a challenge by the Trump administration, the Supreme Court reinstated the restriction.

In March, medical organizations tried again, writing to President Biden and Vice President Harris. In April, the F.D.A. decided not to enforce the in-person requirement for the duration of the pandemic, allowing pills to be mailed. The new F.D.A. decision makes the suspension permanent.

The experience since April suggests that more women will seek medication abortion if they do not have to visit a provider for the pills. Abortion on Demand, which formed this spring as one of several organizations that operate websites to arrange telemedicine consultations and to mail pills, has seen steadily increasing interest, said Leah Coplon, Abortion on Demand’s director of clinical operations.

The TelAbortion Project, the research program authorized by the F.D.A. to conduct telemedicine appointments and mail pills, also heard from more women, said Elizabeth Raymond, senior medical associate at Gynuity Health Projects, which runs the program. She said that of 2,083 abortions provided under the program between July 2016 and October 2021, more than a third — 715 — occurred during the pandemic.

Kirsten Moore, director of the Expanding Medication Abortion Access Project, said abortion rights supporters had hoped that the F.D.A. would also lift the other two restrictions related to mifepristone, especially the requirement that providers be certified, because it means that women won’t necessarily be able to get the pills from their regular doctor or clinic.

Still, Ms. Moore said she hoped that the increased availability of medication abortion would help open up appointments for women who need surgical abortions by creating “more room in the abortion ecosystem for patients who need to get into a clinic.”

Lifting the restrictions on mifepristone would make medication abortion more accessible, but in 19 states that have already banned telemedicine visits for abortion pills, women would probably need to travel to states that allow it.Credit...Jeff Roberson/The Associated Press