Planned Parenthood pulled out of a federally funded family-planning program on Monday over an abortion gag rule, leaving many of its 1.5 million clients scrambling for services.

The move comes after a federal appeals court approved a new Trump administration rule that bars healthcare providers who receive federal funds from performing abortions or referring their patients to abortion providers.

Planned Parenthood’s decision is a victory for anti-abortion activists, who have been attempting to cut off government funding to the organization for years.

“The Trump administration has forced Planned Parenthood grantees out of Title X,” Planned Parenthood Acting President Alexis McGill Johnson told reporters, adding, “We will not be bullied out of providing abortion information to our patients.”

McGill said clinics would remain open, but that patients could experience long wait times and some may choose not to seek care. The organization has said it will seek other sources of funding, such as donations, to attempt to close the gap. Representatives declined to say Monday exactly how much federal funding they would lose.

The Trump administration rule bars any recipient of Title X—a program that provides $286 million in family planning funds for an estimated 4 million low-income Americans each year—from performing abortions or providing referrals to abortion providers, except in the case of a medical emergency.

The Department of Health and Human services, which administers the program, released its own statement Monday, noting that the rule was finalized before the current grants were awarded.

“Some grantees are now blaming the government for their own actions—having chosen to accept the grant while failing to comply with the regulations that accompany it—and they are abandoning their obligations to serve their patients under the program," the department said.

Planned Parenthood, the American Medical Association, the ACLU, and more than 20 states filed challenges to the rule when it was first announced in May, saying it prevents doctors from speaking honestly with their patients. Critics also argued the rule would disproportionately affect low-income people and people of color.

“Those who receive care through Title X are disproportionately low income, about half identify as people of color, and one in ten have limited English proficiency,” Ann Marie Benitez, the senior director of government relations at the National Latina Institute for Reproductive Health, told reporters.

She added, “Our community is often making the hard choice between going to get the healthcare they need when they need it, or putting food on the table or paying their bills. Forcing clinics out of the Title X program makes this much worse.”

Several lower courts blocked the rule—with one federal judge calling it a “ham-fisted approach to public health policy”—but the U.S. Court of Appeals for the Ninth Circuit allowed it to move forward in July.

Planned Parenthood challenged the ruling and announced it would pull out of the program if it was not overturned. On Friday, the court declined to hear the appeal. McGill said all Planned Parenthood affiliates that receive Title X funding would send letters to the Department of Health and Human Services by the end of the day Monday announcing their withdrawal.

Several other legal challenges are still working their way through the courts. The Ninth Circuit will hear oral arguments in these cases the last week of September. The House has also passed a funding bill that would block the rule, but the Senate has yet to vote on it.

While Planned Parenthood serves more than 40 percent of Title X patients, the rule also affects other health-care providers. Democratic governors in five states said they would also pull out of Title X if the restrictions were applied, and two state legislatures have passed laws stating as much.

Public Health Solutions, the largest public health nonprofit in New York City, also rejected Title X funding Monday. Executives said that if they could not make up the difference through fundraising, their patients could experience longer wait times for routine sexual health services—and may forgo them altogether.

“I think this is going to contribute to an uptick in sexually transmitted infections, it will result in people not getting the contraceptives that they want, and an increase in unplanned pregnancies,” President and CEO Lisa David told The Daily Beast.

Providers were already barred from using federal money to fund abortions, but could use it for other services, such as sexually transmitted infection tests, cancer screening, and contraceptives. Approximately 60 percent of women who obtain contraceptives from a Title X-supported center also use it for routine medical care, according to the Guttmacher Institute.

A number of Democratic lawmakers and presidential candidates have expressed their opposition to the rule in recent days. Beto O’Rourke called it “a direct attack on women, their rights, and [Planned Parenthood,]” while Rep. Seth Moulton (D-MA) said the rule is “un-American.”

Andrea Miller, president of the National Institute for Reproductive Health, called Monday's events "the end of Title X as we know it."

Abortion opponents, however, were thrilled with the court’s decision. Marjorie Dannenfelser, president of anti-abortion group Susan B. Anthony List, called the measure the “Protect Life Rule” and said it would stop abortion providers from “treating Title X as their private slush fund.”

“Once again, Planned Parenthood is placing abortion above all else, most especially the low income women they claim to be serving,” Ashley McGuire, a senior fellow with The Catholic Association, said in a statement.