Pain affects approximately two thirds of patients with advanced cancer, with rates approaching 90% near the end-of-life. Although pharmacotherapy is vitally important to alleviating chronic cancer pain, psychological factors also substantially influence pain outcomes. Cognitive Behavioral Therapy for pain (pain-CBT) is effective for chronic cancer and non-malignant pain. Unfortunately, pain-CBT in its traditional format (60minute, in-person sessions for 12-16 weeks) is unrealistic for advanced cancer patients. Effective biopsychosocial cancer pain management requires substantial adaptation to meet the real-life needs of advanced cancer patients and should ideally integrate with pharmacotherapy support. Given the expansive need, mobile health technology is a promising strategy to deliver and ultimately disseminate brief, pain-CBT interventions to cancer patients. Our goal is to improve advanced cancer patients' pain self-management by adapting and integrating pain-CBT into our existing mHealth program designed to support patients' pharmacologic management. Our parent intervention, STAMP (Smartphone Technology to Alleviate Malignant Pain) is a patient-facing smartphone application that supports daily symptom and opioid monitoring, and delivers tailored pain psychoeducation and advice. We have a strategic opportunity to adapt and integrate pain-CBT to create novel mHealth intervention that harmonizes psychological and medical support for advanced cancer pain. Leveraging mobile technology, we will simulate the therapeutic experience of pain-CBT by 1) presenting advanced cancer-specific, multimedia psychoeducational content, 2) developing schedules to deliver daily, brief didactics, 3) facilitating insight building via surveys and tailored feedback, & 4) stimulating active learning through gamified cognitive restructuring exercises and audio-recorded relaxations. In Aim 1: We will supplement our multi-media library of cancer pain psycho-education and adapt pain-CBT content for brief mHealth delivery specific to advanced cancer, while integrating clinician and patient (n=20) feedback throughout. In Aim 2: 25 patients with chronic pain from advanced cancer will use STAMP+CBT for 6 weeks. Findings will illuminate feasibility of app use and data collection for a larger future efficacy trial (R01), allowing for exploration of meaningful trends in pain, psychological mediators, and care utilization. If proven effective, this pain-CBT and opioid management intervention has great potential to scale and make biopsychosocial pain treatment available to a population that suffers disproportionately from chronic pain and has little access to non-pharmacologic pain management treatments.