Background: The Accreditation Council for Graduate Medical Education (ACGME) Outcome Project introduced 6 general competencies relevant to medical practice but fell short of its goal to create a robust assessment system that would allow program accreditation based on outcomes. In response, the ACGME, the specialty boards, and other stakeholders collaborated to develop educational milestones, observable steps in residents' professional development that describe progress from entry to graduation and beyond.
Objectives: We summarize the development of the milestones, focusing on 7 specialties, moving to the next accreditation system in July 2013, and offer evidence of their validity.