UnitedHealth tumbles 12% on WSJ report the DOJ is investigating Medicare billing practices
1. DOJ investigates UNH Medicare billing protocols. Diagnosis recording practices are under scrutiny. 2. Shares fell 11.5% premarket, dragging Dow futures lower. Volatility intensified. 3. Probe examines extra Medicare Advantage payments. Billing practices are questioned. 4. Separate antitrust probe halts UNH's Amedisys acquisition. Legal challenges persist.