Contemporary educational approaches to professionalism do not take into account the dominant influence that the culture of academic medicine has on the nascent professional attitudes, beliefs, and behaviors of medical learners. This article examines formation as an organizing principle for professionalism in medical education. Virtue, the foundation to understanding professionalism, is the habits and dispositions that are fostered in individuals but that are embedded in learning environments. Formation, the ongoing integration of an individual, growing in self-awareness and in recognition of a life of service, with others who share in the common mission of a larger group, depicts this process. One model of formation considers a continuum from novice to more advance stages that is predicated on rules that must be applied in greater contextually shaped situations. Within medical education, formation is the process by which lives of service are created and sustained by learning communities that promote human capacities for intuition, empathy, and compassion. An imagined curriculum in formation would link the lived experiences of mentors and learners with an interdisciplinary set of didactic materials in an intentionally progressive fashion.