['Few studies in surgery have addressed medical knowledge competency training as defined by the Accreditation Council for Graduate Medical Education. As in-training examinations are ubiquitous educational tools for surgical residents in the United States, insights into examination performance may help fill this void. The purpose of this study was to determine the relationship between In-Service Examination performance and training characteristics in plastic surgery.', 'This retrospective cohort study reviewed performance data for the Plastic Surgery In-Service Training Examination for the years 2012 to 2015. Comparisons were made both within and between training pathways by means of Kruskal-Wallis and Mann-Whitney U tests.', 'Data were available for 1367 independent (37.9 percent) and 2240 integrated residents (62.1 percent). Among integrated residents, performance increased with additional years of training (p < 0.001), but no difference existed between postgraduate year-5 and postgraduate year-6 residents (p > 0.05). Similarly, independent resident examination performance increased by year of training (p < 0.001), with no difference between postgraduate year-2 and postgraduate year-3 residents (p > 0.05). At each level of training (postgraduate years 4 to 6), integrated residents outperformed their independent resident colleagues (postgraduate years 1 to 3) (p < 0.001).'] Does performance on a Surgical In-Training Examination vary by Training Year and Pathway?