One tool that holds promise to improve the coordination of patients’ health care is the "care coordination agreement"—a formal, written arrangement between clinicians that defines responsibilities for the coordination of a patient's care. Emerging evidence suggests that these agreements improve timely access to specialty care services, speed feedback to primary care providers about their patients' hospital stays, and improve discharge planning. This project will support research into how independent primary care practices construct and implement care coordination agreements and how useful they find them to be when collaborating with specialty care practices, hospitals, home health agencies, and nursing homes. The findings will help providers use these agreements more effectively and could facilitate implementation of accountable care organizations and bundled payment systems that rely on well-coordinated care.