BACKGROUND AND OBJECTIVES: US medical school curricula continually undergo reform. The effect of formal curricular approaches (course organization and pedagogical techniques) on competence in medicine as measured by the United States Medical Licensing Examinations (USMLE) Step 1, 2, and 3 is not fully understood. The purpose of this study was to investigate the effects of formal curricular approaches in a latent variable path analysis model of achievement-aptitude-competence in medicine.METHODS: Using Association of American Medical Colleges (AAMC) and USMLE longitudinal data (1994--2004) for 116 medical schools, structural equation modeling was used to study latent variable path models assessing the impact of curriculum on competence in medicine (n=9,332). RESULTS: A latent variable path model consisting of three latent variables measured by undergraduate grade point average (general achievement), Medical College Admission Test subscores (aptitude for medicine), and USMLE Step 1--3 (competence in medicine) was used to assess the impact of curriculum on competence in medicine. Two models were tested; one resulted in a Comparative Fit Index=.931 with a path coefficient of 0.04 from curriculum to competence in medicine. While there was a good fit of the data to the final model, the type of school curriculum did not significantly influence competence in medicine since it accounted for less than 1% of the variation in student performance on the USMLE. CONCLUSIONS: Various formal curricular approaches have little differential effect on students' performance on the USMLE.