This report is an evaluation of the i3 development grant Think College Transition (TCT), an inclusive dual enrollment transition model to improve achievement and post-school outcomes for students with intellectual disabilities or autism (ID/A). The model offers an innovative approach to transition services for students with intellectual disabilities and autism by providing participation in inclusive academic and social environments of a college campus with same-aged peers rather than continuing to receive transition services in typical high school environments. This evaluation examined the impact of TCT services on the job-seeking skills, career readiness, self-determination, college self-efficacy, and employment of ID/A youth. A quasi-experimental design was used to compare baseline and end-of-the year data on outcome variables from students with ID/A participating in the TCT model at three institutes of higher education in Massachusetts with students with ID/A participating in business-as-usual transition services through their school districts. The fidelity with which the TCT model was implemented at the intervention sites was also evaluated. Results from the evaluation found that, after controlling for student baseline scores, the TCT model had a significant effect on students' scores of self-determination after one year of participation. This is one of the first quantitative studies to examine college-based transition programs using a rigorous research design. Future research will need to be conducted to learn what TCT model components specifically affect self-determination and what other long-term effects participation in the TCT model might have. [Additional financial support for this research was provided by the Peter and Elizabeth C. Tower Foundation.]