Emerging adulthood is a period of heightened risk for young people with autism spectrum disorder (ASD). Due in part to a lack of evidence-based services and supports during the transition to adulthood, many emerging adults fail to matriculate into postsecondary education or thrive in productive employment. The Stepped Transition in Education Program for Students with ASD (STEPS) was developed to address the psychosocial, transition-related needs of emerging adults with ASD. Adolescents and emerging adults (n = 59) with ASD were randomly assigned to either STEPS or transition as usual (TAU). Results indicate that STEPS is acceptable to young people with ASD and their parents and that it can be implemented with high fidelity. Among secondary school students, those who completed STEPS exhibited significantly greater gains in transition readiness from high school, and these gains were largely sustained after program completion. Among students enrolled in postsecondary education, STEPS resulted in increased levels of student adaptation to college relative to those in TAU. Programming to address ASD-related challenges can promote successful educational transitions.