In most health care institutions, physician peer review is the primary method for maintaining and measuring physician competency and quality of care issues. However, many teaching hospitals do not have a method of tracking resident trainees' involvement in adverse cases. At the study institution, Code R was introduced as a measure to capture resident trainee involvement in the hospital-wide peer review process. The authors conducted a retrospective review of all peer review cases from January 2008 to December 2011 in an academic medical center and determined the quantity and type of resident errors that occurred compared to attending faculty. The Accreditation Council for Graduate Medical Education's core competencies served as a framework to categorize quality of care errors. The addition of Code R to the peer review process can be readily adopted by other institutions to help improve resident education, facilitate faculty supervision, and potentially improve patient safety.