In 2010, several key works in medical education predicted the changes necessary to train modern physicians to meet current and future challenges in health care, including the standardization of learning outcomes paired with individualized learning processes. The reframing of a medical expert as a flexible, adaptive team member and change agent, effective within a larger system and responsive to the community's needs, requires a new approach to education: competency-based medical education (CBME). CBME is an outcomes-based developmental approach to ensuring each trainee's readiness to advance through stages of training and continue to grow in unsupervised practice. Implementation of CBME with fidelity is a complex and challenging endeavor, demanding a fundamental shift in organizational culture and investment in appropriate infrastructure. This paper outlines how member schools of the American Medical Association Accelerating Change in Medical Education Consortium developed and implemented CBME, including common challenges and successes. Critical supporting factors include adoption of the master adaptive learner construct, longitudinal views of learner development, coaching, and a supportive learning environment.