Imposter phenomenon can occur in highly competitive fields causing internal feelings of fraud and self-doubt. Significant imposterism has been recently reported amongst general surgery residents. We hypothesized that attending surgeons, navigating the transition into independent practice, would report a similar experience. We surveyed and collected Clance Imposter Phenomenon Scale (CIPS) scores from 24 Army general surgeons within 4years of graduation. Nearly all exhibited at least moderate imposterism, and over half reported significant or intense imposterism. Women reported statistically higher scores than men. Surgeons who engaged in off-duty employment or participated in mentorship were less likely to have significant or intense imposterism. Transition to practice is a challenging and highly variable time for new surgeons. Identifying factors that attenuate these feelings could help with early career advancement.