2026 Medicare Accountable Care Organization Initiatives Participation Highlights

As of January 2026, 14.3 million Medicare beneficiaries are estimated to receive care coordinated by Accountable Care Organizations (ACOs), up from 13.7 million in 2025, representing a 4.4% increase. ACOs are groups of doctors, hospitals, and other health care professionals that work together to coordinate care for a group of patients with Original Medicare and manage costs. ACOs may be in a specific geographic area and/or focused on patients who have a specific condition, like chronic kidney disease.

When ACOs provide higher quality, coordinated care that improves patient health outcomes and reduces Medicare spending, they may be eligible to share a portion of those savings. Conversely, ACOs could pay a penalty if they provide fragmented care that increases Medicare costs. Examples of ACOs are Medicare Shared Savings Program (Shared Savings Program) and entities participating in Center for Medicare and Medicaid Innovation (CMS Innovation Center) accountable care models, as well as other CMS Innovation Center models focused on total cost of care, advanced primary care, and specialty care. In Performance Year 2024, the most recently reconciled performance year, Shared Savings Program ACOs earned shared savings totaling $4.1 billion and saved Medicare $2.5 billion.