Stepped Transition in Education Program for Emerging Adults with Autism: Pilot Effectiveness Trial - PROJECT SUMMARY The long-term goal of this research is to improve adult outcomes for people with autism spectrum disorder (ASD). Adolescents and young adults with ASD tend to have worse outcomes, with respect to employment, education, and quality of life, than neurotypical peers. These outcomes include under-enrollment into college, unemployment, and limited functional independence. Research-informed transition planning that addresses core impairments in skills related to adult autonomy, including self-knowledge, self-determination, and self- regulation, may improve outcomes for this growing population. In prior research, we developed a stakeholder- involved transition program (STEPS: Stepped Transition in Education Program for Students with ASD) and found it to be feasible, acceptable, and efficacious. Data from a small randomized controlled trial (RCT) focusing on feasibility indicated that it was acceptable to participants and suggested STEPS was effective in improving readiness for transition to adulthood. We will now test the effectiveness of STEPS, and engagement of target mechanisms, in partnership with four community agencies. This study is designed as a Hybrid Type 1, which focuses primarily on intervention effectiveness with a secondary focus on factors related to implementation. We assess the immediate (post-treatment) and longer-term (six month follow-up) clinical outcomes of adult functional outcomes and vocational engagement. We will also determine the degree to which STEPS leads to change in the theoretical mediating mechanisms (i.e., adult autonomy skills) and formally test mediation (i.e., the degree to which change in adult autonomy skills leads to change in adult functional outcomes). From the providers, we will seek qualitative information on implementation such as thoughts on STEPS’ cultural sensitivity, and quantitative data on the appropriateness, feasibility, and acceptability of STEPS. We also track providers’ sustained use of STEPS with their clients in the six months after study enrollment has ended. This research will produce findings that have the potential to shift clinical practice related to transition to adulthood for people with ASD. In light of the fact that approximately 70,000 people with ASD age into adulthood every year and the economic burden associated with ASD, the potential public health impact of this research is considerable.