Medicare will provide coverage for Wegovy for patients with an increased risk of heart attack, stroke or other serious cardiovascular problems, an agency spokesperson said Thursday.

The decision, experts say, could potentially grant millions of patients access to the popular yet expensive weight loss medication.

Medicare, which currently provides health insurance to more than 65 million people in the U.S., has long been barred from paying for weight loss drugs.

Earlier this month, however, the Food and Drug Administration expanded the approval for Wegovy, saying that it can be prescribed to people who are overweight or have obesity to reduce their risk of heart disease.

The change prompted the Centers for Medicare and Medicaid Services to consider coverage because reducing heart disease risk is a medically accepted use under federal law, the spokesperson said.

Medicare will still not cover Wegovy if it is only being used for weight management, the spokesperson said.

Lawrence Gostin, director of the O’Neill Institute for National and Global Health Law at Georgetown University, said Medicare providing coverage for Wegovy is “transformational.”

But doing so could potentially undermine Medicare’s “financial stability,” Gostin said. The drug carries a list price of around $1,200 a month, and many patients will likely want a prescription.

A survey from the University of Michigan National Poll on Healthy Aging in December found about 3 in 4 older adults believe Medicare should cover weight loss medications.

A blog post from the Congressional Budget Office last October said that if Medicare did cover weight loss medications such as Wegovy, the net cost to the program “would be significant over the next 10 years.”

“There could be a slippery slope where Medicare ends up paying for the drug to be used for weight loss purposes,” Gostin said. “That would bankrupt Medicare and cause a taxpayer revolt.”

Juliette Cubanski, deputy director of the Medicare policy program at KFF, a nonpartisan group that studies health policy issues, said that while Medicare won’t cover the drug solely for weight loss, many people with heart disease are overweight or have obesity.

“We could see Medicare patients with both conditions get coverage of this drug for its heart health benefits,” Cubanski said. “That’s potentially a big deal given the large demand for this drug even in the absence of many insurers covering it.”

The drug will be covered under Medicare Part D, which covers the cost of medications people take at home, the spokesperson said.

It’s not clear how private insurance companies that offer supplemental Part D coverage will respond, Cubanski said, noting that plans do have the ability to add new drugs to the list of drugs they cover in the middle of the year, “but given the cost of this drug, plans might not want to be the first movers.”