This study examined rates of and contributing factors to self-determination among young adults with autism spectrum disorder. Caregivers of young adults with autism spectrum disorder, 16-25 years, from five Autism Treatment Network sites completed surveys about their young adults' transition experiences including the American Institutes for Research Self-Determination measure. Data were analyzed using univariate and multivariate analysis. Caregivers (n = 479) reported their young adults with autism spectrum disorder as having moderate overall self-determination (x = 38; standard deviation = 9.04) with low capacity (x = 15.3; standard deviation = 5.67) and high opportunities at home (x = 23.1; standard deviation = 4.59). Young adults with autism spectrum disorder with intellectual disability or severe autism spectrum disorder symptomology experience significant disparities in overall self-determination compared to those without intellectual disability and less frequent symptom expression and severity. Barring severity indicators, there were few significant predictors of self-determination. Findings show a breakdown in self-determination skill-building. Young adults with autism spectrum disorder with intellectual disability or severe symptomology experienced significant disparities in self-determination. These findings show that current promotion of self-determination is not meeting the needs of young adults with autism spectrum disorder. Future interventions must identify what supports young adults with autism spectrum disorder need to capitalize on these opportunities to be independent and exert autonomy in their daily lives.