An Accountable Care Organization (ACO) is a group of doctors and other healthcare providers who agree to work together with Medicare to give Medicare Fee-For-Service Beneficiaries higher quality care.
An ACO isn’t the same as a Medicare Advantage Plan or Health Maintenance Organization (HMO). Medicare beneficiaries are still in Original Medicare, and their Medicare benefits, services, rights and protections won’t change. Medicare beneficiaries still have the right to use any doctor or hospital that accepts Medicare at any time, the same as they do now.
ACO Link at CMS.gov: https://www.cms.gov/Medicare/Medicare-Fee-for-Service-Payment/ACO/