The Department of Justice’s (DOJ) health care fraud unit is investigating UnitedHealth Group (NYSE: UNH) for criminal Medicare fraud, according to a report from the Wall Street Journal (WSJ).

The exact details of the criminal allegations against UnitedHealth Group were not clear, according to the article, but the federal investigation is said to relate to the company’s Medicare Advantage (MA) business.

On its end, UnitedHealth Group denied being notified by the DOJ about the criminal investigation reported by the WSJ.

“We stand by the integrity of our Medicare Advantage program,” UnitedHealth Group wrote in a press statement on Wednesday.

UnitedHealth Group and the DOJ did not immediately respond to Home Health Care News’ request for comments.

UnitedHealth Group is one of the largest companies in the country and has an array of associated business lines. UnitedHealth Group’s provider services arm, Optum, owns home-based care company LHC Group.

Additionally, UnitedHealth Group’s UnitedHealthcare is the nation’s largest MA provider. The company was responsible for 29% of all MA enrollment in 2024. Overall, 32.8 million individuals enrolled in an MA plan last year, according to data from KFF.

If confirmed, this wouldn’t be UnitedHealth Group’s only battle with the DOJ. In late 2024, the DOJ sued UnitedHealth Group to quash its proposed merger with Amedisys Inc. (Nasdaq: AMED), believing that it would negatively impact patients, payers and home health workers.

UnitedHealth Group first entered a deal for Optum to acquire Amedisys for $3.3 billion in 2023.

UnitedHealth Group and Amedisys are scheduled to begin mediation with the DOJ over its plans to acquire the home-based care company on Aug. 18.

The companies have made two attempts to divest assets and mitigate antitrust concerns, including plans to sell home health and hospice assets to the Pennant Group (Nasdaq: PNTG) and BrightSpring Health Services (Nasdaq: BTSG). On Monday, the DOJ reportedly rejected this deal. 

The news of a DOJ investigation also comes right on the heels of UnitedHealth Group’s announcement that Andrew Witty has stepped down as CEO. On Tuesday, the company also revealed that board Chairman Stephen Hemsley — who previously served as CEO from 2006 to 2017 — would be his replacement, effective immediately.