ABSTRACT: Substance use disorder (SUD) among anesthesiologists and other physicians poses serious risks to both physicians and patients. Formulation of policy and individual treatment plans is hampered by lack of data regarding the epidemiology and outcomes of physician SUD.To describe the incidence and outcomes of SUD among anesthesiology residents.Retrospective cohort study of physicians who began training in United States anesthesiology residency programs from July 1, 1975, to July 1, 2009, including 44,612 residents contributing 177,848 resident-years to analysis. Follow-up for incidence and relapse was to the end of training and December 31, 2010, respectively.Cases of SUD (including initial SUD episode and any relapse, vital status and cause of death, and professional consequences of SUD) ascertained through training records of the American Board of Anesthesiology, including information from the Disciplinary Action Notification Service of the Federation of State Medical Boards and cause of death information from the National Death Index.Of the residents, 384 had evidence of SUD during training, with an overall incidence of 2.16 (95% CI, 1.95-2.39) per 1000 resident-years (2.68 [95% CI, 2.41-2.98] men and 0.65 [95% CI, 0.44-0.93] women per 1000 resident-years). During the study period, an initial rate increase was followed by a period of lower rates in 1996-2002, but the highest incidence has occurred since 2003 (2.87 [95% CI, 2.42-3.39] per 1000 resident-years). The most common substance category was intravenous opioids, followed by alcohol, marijuana or cocaine, anesthetics/hypnotics, and oral opioids. Twenty-eight individuals (7.3%; 95% CI, 4.9%-10.4%) died during the training period; all deaths were related to SUD. The Kaplan-Meier estimate of the cumulative proportion of survivors experiencing at least 1 relapse by 30 years after the initial episode (based on a median follow-up of 8.9 years [interquartile range, 5.0-18.8 years]) was 43% (95% CI, 34%-51%). Rates of relapse and death did not depend on the category of substance used. Relapse rates did not change over the study period.Among anesthesiology residents entering primary training from 1975 to 2009, 0.86% had evidence of SUD during training. Risk of relapse over the follow-up period was high, indicating persistence of risk after training.