The disclosure sent UNH shares tumbling 4.7%, reflecting investor unease with the ongoing troubles with the healthcare stock. This admission adds to a string of challenges that have battered the company, with its stock now trading 56% below its 52-week high.

UnitedHealth confirms the DOJ is investigating its Medicare billing practices. Here's how that may affect UNH share price moving forward.

UnitedHealth (UNH) shares inched down on Thursday after the insurance giant confirmed the U.S. Justice Department is investigating its Medicare billing practices. The DOJ is investigating whether the NYSE-listed firm artificially inflated Medicare reimbursements by overstating or exaggerating patient health conditions.