UnitedHealth Group is one of the largest private health insurers and provides medical benefits to about 51 million members globally, including 1 million outside the US as of December 2025. As a leader in employer-sponsored, self-directed, and government-backed insurance plans, UnitedHealth has obtained massive scale in medical insurance. Along with its insurance assets, UnitedHealth's Optum franchises help create a healthcare services colossus that spans everything from pharmaceutical benefits to providing outpatient care and analytics to affiliates and third parties.