Most institutional studies of science have focused on the functioning of its reward system. Less is known about perspectives scientists develop on their variously rewarded and recognized careers. This study examines people's subjective appraisals of attainment in academic science based on a sample of interviews with physicists who discussed their perspectives on success, including the most salient self-doubts they experience in their roles. The sample is divided into achievement echelons to see how self-doubts vary among those throughout the strata of science. Self-doubts about work accomplishment grip scientists across productivity strata, but these self-doubts grow more uniform as productivity increases. The most diverse sources of self-doubt are found among the least productive scientists in advanced professional ranks.