Although the mistreatment of medical students is a well-researched topic, the scope of mistreatment often leaves out neglect, a subtype for which there is no accepted definition based in the published literature. This review sought to summarize the existing data on the prevalence and descriptors of neglect, identify strategies seen in the literature designed to improve it, and offer a synthesized definition of this phenomenon to guide future research. Following PRISMA guidelines, a relevant systematic literature search from 2000 to April 2021 was performed to identify literature on neglect in clinical settings within American medical schools. Neglect, a poorly defined phenomenon in medical education related to the suboptimal learning environment, is often excluded from research on medical student mistreatment. Neglect is a barrier to a successful learning environment, yet a paucity of data and the heterogeneous nature of the present literature render it difficult to estimate its true prevalence. Studies that include neglect frequently assess it solely as the result of identity discrimination or stated career interests. Recent interventions include promoting longitudinal relationships between students and clinical faculty and establishing teaching expectations. Neglect is the mistreatment of medical students by the medical care team via a lack of meaningful inclusion in the clinical environment such that it has a notable negative impact on learning and student well-being, regardless of intentionality. An established definition that is grounded in the literature is required to create a common point of reference and understand its true prevalence, its associated variables, and the best mitigation strategies, as well as to guide future research, which should examine neglect independently and as a consequence of personal and professional identities.