University Hospitals and Aetna, the third largest U.S. health insurer, have launched an accountable care organization collaboration (ACO) designed to coordinate care and reduce costs for participants enrolled in the insurer's health plans. The ACO, which launched July 1, covers 22,000 Aetna members who currently receive care from UH physicians. It is UH's sixth ACO in the state and Aetna's fifth. ACOs are a cost-saving method of delivering care by a network of doctors and hospitals created by the Affordable Care Act. The main goal of an ACO is to reduce cost with better communication among all the doctors involved in a patient's care, by improving quality, outcomes and patient experience, and by advocating wellness and preventive care.