UnitedHealth Group is under investigation by the U.S. Department of Justice, the company announced on Thursday. This investigation includes both criminal and civil inquiries related to its Medicare practices. In a filing with the Securities and Exchange Commission, UnitedHealth stated it is cooperating with the DOJ's requests. The company reached out to the DOJ after media reports surfaced about the investigation.

"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 in its statement.

This investigation adds to a challenging year for UnitedHealth, the largest healthcare company in the U.S. The company has faced scrutiny since the fatal shooting of its CEO, Brian Thompson, in New York last December. This incident sparked widespread discussions about frustrations with healthcare providers.

In May, reports indicated that the DOJ's healthcare-fraud unit was looking into potential Medicare fraud involving UnitedHealth. The investigation also includes possible antitrust violations and issues related to the company's Medicare billing practices. Following these revelations, UnitedHealth's stock price fell significantly, making it the worst performer on the Dow Jones Industrial Average in the first half of 2025.

The company's stock dropped by 1.5 percent in morning trading after the announcement of the investigation. UnitedHealth emphasized its commitment to maintaining the integrity of its business practices. It noted that a court-appointed monitor had found no wrongdoing after a decade-long investigation 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 stated. The DOJ has not yet responded to requests for comment regarding the investigation. This story is still developing, and updates will be provided as more information becomes available.