UnitedHealth Group faces a criminal and civil investigation from the Department of Justice, the company disclosed on Thursday.

The company in an SEC filing said it was complying with the requests from the DOJ. UnitedHealth said it reached out “proactively” to the DOJ after media reports about a probe into its Medicare practices.

“The Company has now begun complying with formal criminal and civil requests from the Department. The Company has full confidence in its practices and is committed to working cooperatively with the Department throughout this process,” UnitedHealth said.

UnitedHealth’s announcement that it faces a federal investigation adds to an increasingly tumultuous year for the country’s largest healthcare company.

The company was thrown into the spotlight after last year’s fatal shooting of UnitedHealthcare CEO Brian Thompson in New York, sparking a national conversation about frustrations with healthcare companies.

UnitedHealth Group’s CEO abruptly left the company in May, and the company’s stock price plunged following a series of reports in The Wall Street Journal about civil and criminal probes into the company. The WSJ reported in May that the DOJ’s healthcare-fraud unit was investigating possible Medicare fraud at the company, adding to investigations of potential antitrust violations and its Medicare billing practices.

The company was the worst performer on the Dow Jones Industrial Average during the first half of 2025. Its stock price declined by 1.5 percent in morning trading following the announcement.

In a filing with the Securities and Exchange Commission, UnitedHealth said it has “full confidence” in its practices. It added that a court-appointed monitor found no wrongdoing after a decade-long probe into its Medicare Advantage business.

“The Company is committed to maintaining the integrity of its business practices and serving as reliable stewards of American tax dollars,” UnitedHealth said.

The Department of Justice did not immediately respond to a request for comment.

This is a developing story. Check back for updates.