Despite the strong evidence basis for the treatment of anxiety in autistic youth, accessibility remains a significant challenge. Stepped care addresses this gap, although there is limited research into its broad effects in autistic youth with anxiety. In this project, 76 autistic youth with anxiety entered parent-led-bibliotherapy for 12 weeks; 44 stepped up to receive therapist-led cognitive behavioral therapy (CBT). Those who did not step up entered a maintenance phase. Youth were assessed for externalizing and depressive symptoms at mid-treatment, post-treatment, and 3 months after treatment (3MFU). Focal symptoms decreased across groups at all timepoints; those who entered maintenance experienced greater decreases. At 3MFU there were no differences between groups. Parents were assessed for depression, anxiety, and stress at the same timepoints; no significant changes were observed.