Objective: This study examined the utility of social–cognitive career theory (SCCT; Lent, Brown, & Hackett, 1994) as a framework to investigate career self-efficacy, outcome expectations, goals, and contextual supports and barriers as predictors of choice actions among transition-age individuals with epilepsy. Moreover, these SCCT constructs are offered as an operational definition of work participation in this population. Method: Using a quantitative descriptive research design and hierarchical regression analysis (HRA), 90 transition-age individuals with epilepsy, age 18–25, were recruited from affiliates of the Epilepsy Foundation and invited to complete an online survey comprised of a series of self-report social–cognitive measures. Results: The HRA findings indicated that self-efficacy, outcome expectations, and environmental supports were significant predictors of work participation in youth and young adults with epilepsy. The final model accounted for 58% of the variance in work participation, which is considered a large effect size. Conclusions: The research findings provide support for the use of the SCCT framework to identify predictors of work participation and to provide guidance for designing customized vocational rehabilitation services and career development interventions for individuals with epilepsy in the transition from adolescence to adulthood.