CMS released participation data Feb. 4 for Medicare accountable care organizations in 2026, showing continued growth in enrollment and a record number of beneficiaries served by the Shared Savings Program.
Six things to know:
- An estimated 14.3 million Medicare beneficiaries are receiving care coordinated by ACOs as of January 2026, up from 13.7 million in 2025, a 4.4% increase. That figure spans MSSP ACOs, CMS Innovation Center accountable care models and other models focused on total cost of care, primary care and specialty care.
- The Shared Savings Program grew to 511 ACOs in 2026, up from 476 in 2025. CMS approved 134 applications for the program, including 72 new ACOs and 62 renewing or reentering ACOs. Those ACOs include more than 700,000 providers.
- MSSP ACOs will serve 12.6 million traditional Medicare beneficiaries in 2026, a 12.3% increase from 2025 and the largest number ever served by the program.
- In performance year 2024, MSSP ACOs earned $4.1 billion in shared savings and saved Medicare $2.5 billion relative to benchmarks.
- ACO REACH has 74 ACOs with 125,909 healthcare providers and organizations serving an estimated 1.7 million traditional Medicare beneficiaries in 2026. The model includes 614 federally qualified health centers, rural health clinics and critical access hospitals.
- The Kidney Care Choices model includes 74 kidney contracting entities with 7,534 participating providers, serving 237,000 beneficiaries with chronic kidney disease and end-stage renal disease. The ACO Primary Care Flex model includes 23 ACOs serving 359,720 beneficiaries.
