"DOJ Launches Antitrust Probe into UnitedHealth, Stock Falls"

The U.S. Department of Justice has initiated an antitrust investigation into UnitedHealth Group, focusing on its relationships between the UnitedHealthcare insurance unit and its Optum health services arm, as well as its Medicare billing practices. The investigation comes amid concerns about rising healthcare costs and the role of pharmacy benefit manager middlemen. The company's acquisition of Change Healthcare and a recent cybersecurity attack at the billing and data systems provider have also drawn attention. UnitedHealth and the DoJ declined to comment, and the company's shares closed 2.3% lower following the news.