Medicare Advantage Corporate Governance UnitedHealthcare Medicaid Health Insurance UnitedHealth Group Claims Processing Medicare Healthcare System Market Performance Medical Care Leadership Defamation Medicare Advantage Plans Mergers and Acquisitions Claims Medical loss ratio Managed Care UnitedHealth Health Plan Enrollees Medical Care Provider Services Medical Costs Drug coverage Drug discounts PBM Pharmacies Drug Coverage Medical Claims Processing Pharmacy Benefit Managers Cybersecurity Financial Implications Challenges Response Strategic Decisions Cyberattack Impact CVS Health Company Performance Employer Health Benefits Cigna Corporate Leadership Insurance Executives Claim Denial Practices