The National Association of ACOs (NAACOS) represents more than 12 million beneficiary lives through hundreds of organizations participating in population health-focused payment and delivery models in Medicare, Medicaid, and commercial insurance. Models include the Medicare Shared Savings Program (MSSP), Next Generation ACOs, and alternative payment models supported by a myriad of commercial health plans and Medicare Advantage. NAACOS is a member-led and member-owned nonprofit organization that works on behalf of health systems and physician provider organizations across the nation participating in population health-focused payment models to improve quality of care, outcomes, and healthcare cost efficiency.