The Accreditation Council for Graduate Medical Education has partnered with member boards of the American Board of Medical Specialties to initiate the next steps in advancing competency-based assessment in residency programs. This initiative, known as the Milestone Project, is a paradigm shift from traditional assessment efforts and requires all pediatrics residency programs to report individual resident progression along a series of 4 to 5 developmental levels of performance, or milestones, for individual competencies every 6 months beginning in June 2014. The effort required to successfully make this shift is tremendous given the number of training programs, training institutions, and trainees. However, it holds great promise for achieving training outcomes that align with patient needs; developing a valid, reliable, and meaningful way to track residents' development; and providing trainees with a roadmap for learning. Recognizing the resources needed to implement this new system, the authors, all residency program leaders, provide their consensus view of the components necessary for implementing and sustaining this effort, including resource estimates for completing this work. The authors have identified 4 domains: (1) Program Review and Development of Stakeholders and Participants, (2) Assessment Methods and Validation, (3) Data and Assessment System Development, and (4) Summative Assessment and Feedback. This work can serve as a starting point and framework for collaboration with program, department, and institutional leaders to identify and garner necessary resources and plan for local and national efforts that will ensure successful transition to milestones-based assessment.