The Accreditation Council for Graduate Medical Education's (ACGME's) general competency and outcome assessment initiative (i.e., the ACGME Outcome Project) is an effort to enhance residency education and accreditation effectiveness by increasing emphasis on educational outcomes. The Project is also a response to concerns about new graduates' ability to meet the demands of today's practice environment. The competencies emphasize learning in new domains (e.g., Practice-Based Learning and Improvement and Systems-Based Practice) and more traditional ones (e.g., Patient Care and Medical Knowledge). Outcome assessment will provide evidence of residency program educational effectiveness and information to guide improvement. This paper discusses the development and implementations of assessment methods appropriate to evaluate the performance of residents in each of the core competencies.