On February 3, 2016, the federal Centers for Medicare & Medicaid Services (CMS) released a proposed rule to modify the Medicare Shared Savings Program (MSSP) accountable care organization (ACO) benchmark, moving from one based on the individual ACO’s baseline cost performance to a regional baseline. The goal is to encourage ACOs to continue to investment in care coordination and quality improvement. CMS made the change because provider organizations involved in ACOs had contended that the current structure was unsustainable in the long-term because they might not be able to continually improve against their own baseline. Some said the . . .