Starting in 2026, CMS is introducing major updates to the Medicare Shared Savings Program (MSSP) that will impact ACO participation, risk models, quality reporting, and cybersecurity protections. Key changes include a shorter one-sided risk period (5 years instead of 7), relaxed patient minimums, simplified quality reporting, and new safeguards against cyberattacks. ACOs must prepare now to adapt to these shifts and maximize performance under the new rules.

The 2026 CMS proposed rule introduces major updates for ACOs in the Medicare Shared Savings Program (MSSP), including mandatory APP reporting, a stronger push toward digital quality measures, and higher performance thresholds. Key changes also include revised benchmarking, beneficiary attribution adjustments, and expanded Promoting Interoperability requirements. ACO leaders should prepare for increased digital reporting demands while taking advantage of new flexibilities—especially for rural and smaller ACOs. Stay informed and ready for compliance ahead of the final rule.