KEY POINTS

UnitedHealth Group revealed it is facing Justice Department criminal and civil investigations over its Medicare billing practices, adding to a string of setbacks for a company that owns America’s largest and most powerful private insurer.

UnitedHealth also said it has launched a third-party review of its business policies and performance metrics.

It comes after a tumultuous last year for UnitedHealthcare, the nation’s largest and most powerful private health insurer.