MSSP and ACO Proposed Changes 2026: What Clinicians Need To Know About Proposed Rule Changes

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.