Health care delivery must be transformed to manage spiraling costs and preserve quality care. Transforming complex health systems will require the engagement of physicians as leaders in their health care settings, in both formal and informal roles. In this article we explore the experience of physician leader engagement and identify factors operating at the individual, team, and organizational levels related to increased or decreased physician leader engagement. Using an inductive approach, our analysis of the transcribed interviews yielded a rich understanding of what motivates physicians to be engaged as leaders, how they experience engagement, the role of the physician leader, how physicians understand other physicians' engagement, what encourages and discourages their engagement efforts, and the role that education and training has in physician engagement. We conclude by offering strategies that physicians, health care organizations, and educational institutions can implement to increase the engagement of physician leaders.