Coordinated care is a defining principle of primary care, but it is becoming increasingly difficult to provide as the health care delivery system in the United States becomes more complex. To guide recommendations for research and practice, the evidence about implementation of coordinated care and its benefits must be considered. On the basis of review of the published literature this article makes recommendations concerning needs for a better-developed evidence base to substantiate the value of care coordination, generalist practices to be the hub of care coordination for most patients, improved communication among clinicians, a team approach to achieve coordination, integration of patients and families as partners, and incorporation of medical informatics. Although coordination of care is central to generalist practice, it requires far more effort than physicians alone can deliver. To make policy recommendations, further work is needed to identify essential elements of care coordination and prove its effectiveness at improving health outcomes.