Despite widespread endorsement of competency-based assessment of medical trainees and practicing physicians, methods for identifying those who are not competent and strategies for remediation of their deficits are not standardized. This literature review describes the published studies of deficit remediation at the undergraduate, graduate, and continuing medical education levels. Thirteen studies primarily describe small, single-institution efforts to remediate deficient knowledge or clinical skills of trainees or below-standard-practice performance of practicing physicians. Working from these studies and research from the learning sciences, the authors propose a model that includes multiple assessment tools for identifying deficiencies, individualized instruction, deliberate practice followed by feedback and reflection, and reassessment. The findings of the study reveal a paucity of evidence to guide best practices of remediation in medical education at all levels. There is an urgent need for multiinstitutional, outcomes-based research on strategies for remediation of less than fully competent trainees and physicians with the use of long-term follow-up to determine the impact on future performance.