Anxiety disorders are among the most common co-occurring psychiatric conditions for youth with ASD (van Steensel et al. in Clin Child Fam Psychol Rev 14:302-317, 2011). Although modified cognitive behavioral therapies (CBT) have yielded significant reductions in anxiety, substantial disparities in access to mental health services exist for youth from diverse and low-income families. Schools represent a consistent resource for underserved communities; thus, there is a critical need to adapt and implement CBT programs in school settings. Engaging stakeholders in the initial phase of adaptation is essential to support adoption and sustainability of best practice interventions in schools. The primary purpose of the study was to adapt group CBT (Facing Your Fears (FYF); Reaven et al. in Facing your fears: group therapy for managing anxiety in children with high-functioning autism spectrum disorders, Paul Brookes Publishing, Baltimore, 2011) via iterative processes with key stakeholders to create a feasible, effective, and sustainable school-based program to manage anxiety in underserved students with ASD. Two rounds of parent and professional focus groups were conducted across three school districts (total 14 groups), using qualitative content analysis methodology. Details regarding the delivery of FYF, selection of students, training considerations for staff, and identifying meaningful outcomes were obtained in anticipation of an implementation trial of FYF.