The risks and benefits of including dual Medicare–Medicaid enrollees in Medicaid accountable care organizations are weighed in a new brief from the Center for Health Care Strategies (CHCS). Prepared with Commonwealth Fund support, the paper also reviews early state experiences with enrolling duals, a population requiring complex and often costly care. Also see the CHCS ACO resource page and, on The Commonwealth Fund Blog, “A Unicorn Realized? Promising Medicaid ACO Programs Really Exist,” by CHCS’s Tricia McGinnis.