Students’ academic self-concepts (ASC) and their orientation towards self-regulated learning are important elements of success. Despite this fact, little work has been conducted exploring these areas medical students. Given the shifting priorities of medical education toward competency-based education and self-directed learning, the goals of this study were to validate an existing measure of ASC and to improve our measurement capabilities for understanding the Master Adaptive Learner (MAL). Evidence for validity and scale reliability was collected for the ASCS with this novel population and a range of motivational and self-regulative variables (Goal orientation, academic emotion regulation, and lifelong learning) were analyzed and reduced to produce a single scale for MAL. Surveys were administered to 203 medical students at an urban, Mid-Atlantic medical school and students’ grades were linked to survey responses. Results of a confirmatory factor analysis indicated that the original factor structure was not a good fit to the data for the current data. An exploratory factor analysis (EFA) was conducted to identify which structure fit better, and while a three-factor structure was produced, only one factor met reliability standards. This factor, confidence, was merged with items from the other surveys, and reliability scores for a composite MAL scale were identified. Based on these findings and the result of an EFA, the total item pool was reduced from 83 to 25. These 25 items discriminated between two clusters of students: MALs and others. Students’ membership in the MAL cluster predicted greater performance on the first exam in medical school, but not on any other grade outcomes. These results provide early evidence for the continued study of MAL and motivation in medical school, which will help researchers and curriculum designers support the development of future physicians.