This project will implement and evaluate two evidence-informed supports for improving treatment engagement for transition-age youth: a transition care coordination process that will utilize a young adult peer provider in the role of a transition navigator; and a transition-age youth supported employment/education specialist to augment other mental health services. These two supports will work across the child-and-adult mental-health services and integrate with the transition-age youth’s existing care team throughout the transition phase. The study will consist of a process and outcome evaluation, mixed-methods study, of the transition care coordination process implementation.