High school administrators in a rural school district were providing transition planning to students with autism spectrum disorder (ASD) in order to meet postschool transition goals. Despite these efforts, few students with ASD were employed or enrolled in postsecondary training, and parents reported that they were dissatisfied with the postschool transition process. The purpose of this collective case study was to explore parental and staff perceptions of the postschool transition processes of students with ASD to increase the understanding of the practice related to postschool transitions. Guided by Tinto and Pusser's institutional framework, research questions were focused on the experiences of parents and staff, including teachers and support personnel, with the postschool transition process of students with ASD. A purposeful sample of 25 participants, including the first 10 parents of students with ASD who applied and the staff who supported them, were interviewed. Teachers were also observed during the postschool transition process. Archival postschool transition survey data were also analyzed. Themes were identified through application of open coding and thematic analysis to interviews, observations, and survey data and included: parents and teachers need support [reference guide and professional development (PD)] and stakeholder collaboration is crucial to success even though time is a constraint and skills prioritization is evident in Individualized Education Plans (IEPs). Teachers used IEPs to guide the postschool transition process, but parental concerns remained. Therefore, a PD for teachers and reference guide for parents were created for the local site to improve parental trust of the postschool transition process for students with ASD.