In a new policy research brief by the Geiger Gibson/RCHN Community Health Foundation Research Collaborative, “Medicare’s Accountable Care Organization Regulations: How Will Medicare Beneficiaries who Reside in Medically Underserved Communities Fare” the authors examine the impact on medically underserved Medicare beneficiaries of the Centers for Medicare and Medicaid Services (CMS’) proposed rule implementing the Medicare Shared Savings Program (MSSP) for Accountable Care Organizations (ACOs).