The following study evaluates the associations between primary care team communication, interaction, and coordination (ie, social networks); quality of care; and costs for patients with cardiovascular disease. Teams with dense interactions among all team members were associated with fewer hospital days and lower medical care costs for patients with cardiovascular disease. Conversely, teams with interactions revolving around a few central individuals were associated with increased hospital days and greater costs. Team-shared vision about goals and expectations mediated the relationship between social network structures and patient quality of care outcomes.