This study will evaluate the efficacy of an eight-module, online, self-directed treatment for chronic pain using Acceptance-Based Behavioural Therapy (ABBT) as the treatment modality. The online modules are tailored to the unique issues of individuals with a military background. The modules will be delivered via the WebCAPSI Therapy program, an online, password-protected program that allows participants to anonymously progress through all modules at their own pace. ABBT modules cover the following: Introduction, Acceptance, Values, Cognitive Defusion, Mindfulness, Exercise/Pacing/Communication Skills, Self-as-Context, and Willingness. Modules encourage understanding of the information through audio files, military-specific vignettes, written materials, and homework exercises. Modules are designed to be completed in 60 minutes or less. Participants will have access to the online treatment for a three month period and will be encouraged to complete one module per week.