The nation’s 3rd largest health insurance company, Aetna, made formal Monday its plan to severely limit its participation on the public exchange marketplaces created by the Affordable Care Act.

In 2017, the health care giant will scale back its presence by around two-thirds of its current footprint and accept exchanges in only four states: Delaware, Iowa, Nebraska and Virginia. Currently, around 11 million Americans have obtained coverage through the online exchange program, which grants eligible lower-income consumers money through tax credits and other subsidies to help buy them individual insurance plans. Aetna’s decision was seemingly spurned by the continuing financial losses incurred by participating in the program, which totalled $430 million in individual products since the program formally began in January 2014, according to Mark T. Bertolini, the chairman and chief executive of Aetna.

“As a strong supporter of public exchanges as a means to meet the needs of the uninsured, we regret having to make this decision,” Bertolini said in a statement announcing the cutbacks.

Though Aetna isn’t the first large insurer to pull back from the exchange marketplaces, Obamacare advocates like Senator Elizabeth Warren (D-Mass) have offered a different reason for the move, which was a reversal of the company’s position earlier this year: Retaliation over the federal government’s legal attempt to block a planned merger between Aetna and the health insurer Humana, citing fears it would create a monopoly and possibly increase insurance costs (it has also sued to prevent a similar merger between Anthem and Cigna, the second and fourth-largest insurers respectively).

“Aetna may not like the Justice Department’s decision to challenge its merger, and it has every right to fight that decision in court. But violating antitrust law is a legal question, not a political one,” said Warren in a Facebook post last week after it was reported that Aetna would reconsider its stance. “The health of the American people should not be used as bargaining chips to force the government to bend to one giant company’s will.”

Whatever the reason, government officials have stated the overall health of the marketplace will not be negatively impacted by Aetna’s move.

“Aetna’s decision to alter its Marketplace participation does not change the fundamental fact that the Health Insurance Marketplace will continue to bring quality coverage to millions of Americans next year and every year after that,” said the administration’s ObamaCare marketplace CEO, Kevin Counihan.