The primary purpose of this investigation was to understand the influence of access to the general curriculum on the performance of students with significant cognitive disabilities, as measured by the Wisconsin Alternate Assessment (WAA) for Students with Disabilities. Special education teachers (N = 113) submitted case materials for students with significant disabilities who were assessed using the WAA. Cases included WAA rating scales, students’ individualized education programs (IEPs), and a curricular access questionnaire. Structural equation modeling was used to examine the influence of curricular access on students’ WAA performance. Students’ scores on the WAA Reading, Language Arts, and Mathematics scales were included in the model as the indicators for the latent factor—student performance. Student grade level, teacher reports of students’ curricular access, percentage of academic focused IEP goals, and time spent in general education settings were included as predictors of students’ performance. Results indicated the model accounted for 41% of the variance in the latent factor of student performance. Implications of these results are discussed for the validity of WAA scores and the design of professional development and teacher support materials.