One of Maine’s three health care insurers says it will begin to “surgically extract” itself from the individual marketplace if changes aren’t made to the Affordable Care Act.

Anthem CEO and President Joseph R. Swedish sent a letter to Republican leaders in Congress this month, telling them it is increasingly difficult for his company to stay in the individual market.

“As I have said publicly, without significant regulatory and statutory changes to the individual market, we will be begin to ‘surgically extract’ Anthem from that market beginning in 2018,” Swedish wrote to Rep. Greg Walden, R-Ore., chairman of the House Energy and Commerce Committee, and to Rep. Kevin Brady, R-Texas, chairman of the House Ways and Means Committee.

In the letter dated March 9, Swedish cited provisions of the American Health Care Act promoted by President Trump and House Speaker Paul Ryan that he believed would address the challenges facing the ACA. The Republican leadership abandoned the plan on Friday when it became clear it wouldn’t pass a House vote.

Maine Community Health Options and Harvard Pilgrim Health Care are Maine’s two other ACA marketplace insurance providers.

Community Health Options has about 50,000 of the roughly 80,000 Mainers with insurance on the individual marketplace. Anthem and Harvard Pilgrim have the rest.