Accountable care organizations (ACOs) are groups of doctors, hospitals, and other healthcare providers, including senior living communities, who come together voluntarily to give coordinated high-quality care to their Medicare patients. Coordinated care helps ensure that patients, especially the chronically ill, get the right care at the right time, with the goal of avoiding unnecessary duplication of services and preventing medical errors. When an ACO succeeds in both delivering high-quality care and spending health care dollars more wisely, it will share in the savings it achieves for the Medicare program.