Illness self-management encompasses a set of key self-care behaviors essential for medical management, reduction of disability and enhancement of quality of life of those suffering from chronic non-cancer pain. The biopsychosocial model, which explores the biological, psychological, and social aspects of functioning, facilitates clinician understanding of the barriers to self-management. Functional conceptualization based on the biopsychosocial model informs treatment planning and seamlessly integrates with a multidisciplinary treatment approach considered the best practice in the management of chronic pain disorders. This article will briefly explore the history of the biopsychosocial model, relay the major tenants of rational emotive behavior therapy (REBT), and propose an expanded biopsychosocial model (rational emotive behavior therapy-health) for the assessment and conceptualization of those suffering from chronic pain disorders. Detailed are specific interview topics and related questions important to the assessment of client functioning with emphasis REBT hypothesis formulations. Discussion of conceptualization will integrate perspectives from the biopsychosocial interview with the addition of REBT hypothesis formulations.