Who UnitedHealth buys from and sells to
Largest US health insurer (UnitedHealthcare) that also runs a PBM, care delivery and data business (Optum).
Buys from 3
- HCA HealthcareHCAhospital care paid for under UnitedHealthcare contracts
- Eli LillyLLYGLP-1 drugs and rebates on the Optum Rx formulary
- Physician groups and health systemsoutpatient and specialist care for members
Sells to 3
- CMS (Medicare and Medicaid)Medicare Advantage and managed Medicaid premiums44% of revenue (FY2025 10-K)
- Employerscommercial health plans and Optum Rx pharmacy benefits
- State Medicaid agenciesmanaged Medicaid contracts
Where the chain could break
- CMS premiums were 44% of 2025 revenue; annual MA rate notices move margins
- Medical cost trend (utilisation, coding audits) hits margins before premiums reset
Competes with
- CVS HealthCVSAetna plans and the Caremark PBM
- CignaCIExpress Scripts PBM and employer plans
- Elevance HealthELVcommercial and Medicaid health plans
- HumanaHUMMedicare Advantage
Mapped by hand from filings and company reporting, as of October 2026. It shows the relationships that matter most, not every contract: most are never disclosed, and agreements change.