My presentation will focus on the development and evaluation of a novel digital intervention for treating posttraumatic stress disorder (PTSD) through a guided self-help (GSH) adaptation of Cognitive Processing Therapy (CPT). GSH therapies provide clients with structured, evidence-based resources accessible online, facilitating independent use with minimal therapist involvement. Although effective psychological treatments for PTSD exist, nearly half of those affected cannot access them due to stigma and negative perceptions of mental health, logistical and financial barriers such as transportation and cost, and long waitlists. The current study is the first randomized controlled trial evaluating the effectiveness of CPT delivered in a GSH format in a stepped care framework. Conducted with 92 adults across Australia who were diagnosed with full or subthreshold PTSD, the study assesses the feasibility, effectiveness, and acceptability of CPT-GSH versus standard CPT (randomization on a 2:1 ratio). GSH participants received twelve modules, covering the content typically delivered in standard CPT sessions. These modules, along with practice assignments, were emailed to participants, who completed them independently on a weekly basis. Therapists provided brief feedback via email to support the participants’ progress, creating a flexible, low-intensity intervention. If participants showed little to no significant improvement, they were stepped up to standard CPT for more intensive treatment. Preliminary analysis indicates promising results, with significant reductions in PTSD and depression symptoms for both intent-to-treat and completer samples (p < .005). Notably, despite the high baseline severity of PTSD symptoms in most participants, all 22 individuals who completed the GSH protocol reached remission status for PTSD. Of the 15 participants who were subsequently stepped up to standard CPT, 66% showed similar positive outcomes, while 17 disengaged without fully completing the GSH protocol. Cost outcomes will also be presented, demonstrating savings associated with this model of care and delivery. This presentation will highlight the potential of digital mental health solutions in providing effective, scalable treatment for PTSD, offering an alternative that is both cost-effective and accessible. The findings are particularly relevant for communities with limited mental health resources, where the scalability and flexibility of digital interventions could improve treatment accessibility and reduce barriers to care. The potential for harnessing further digital innovation (e.g., AI-generated feedback) will be discussed. By showcasing this innovative adaptation of CPT in a digital format, my presentation aims to contribute to ongoing conversations on the future of digital mental health. It will demonstrate how technology can be leveraged to scale mental health interventions, offer more accessible care, and ultimately improve outcomes for those affected by PTSD.