This study presents findings from a pilot randomized controlled trial, testing a 12-week intervention to train parents of youth with autism spectrum disorder (ASD) to advocate for adult disability services--the Volunteer Advocacy Program-Transition (VAP-T). Participants included 41 parents of youth with ASD within 2 years of high school exit, randomly assigned to a treatment (N = 20) or wait-list control (N = 21) group. Outcomes, collected before and after the intervention, included parental knowledge about adult services, advocacy skills-comfort, and empowerment. The VAP-T had acceptable feasibility, treatment fidelity, and acceptability. After participating in the VAP-T, intervention parents (compared to controls) knew more about the adult service system, were more skilled/comfortable advocating, and felt more empowered.