PROJECT SUMMARY Despite a range of therapeutic approaches, chronic musculoskeletal pain (CMP) continues to be a major health issue. It is the most common type of chronic pain, occurring particularly in the joints and back, lasting beyond normal healing (3-6 months). In 2016, 20% of American adults reported chronic pain and 8% of them had limited life activities. Pharmacotherapy is the predominant treatment for chronic pain in current US medical practice, but it has led to the current opioid crisis. Building upon our prior work and lessons learned, we intend to maximize the usability and accessibility of APA. First, we will advance our previous smartphone app by developing a self-guided mobile/web-enabled APA app (mAPA) version on a computer, tablet, or smartphone to allow participants to access APA information based on their preferences and learn to self-administer APA. mAPA will include shortened videos (~1 min) to facilitate micro-learning and incorporate ecological momentary assessment to monitor adherence and capture real-time pain outcomes and analgesic use. Then, we will evaluate the efficacy of mAPA on CMP outcomes through a 3- armed RCT: (1) Self-guided mAPA, (2) In-Person Training + mAPA, and (3) Wait-List Usual Care Control. Participants in the two mAPA groups will continue to receive usual care while participants in the Usual Care Control group will be re-randomized into either mAPA group after 1-month follow-up. Compared to our pilot study, this is a larger scale and longer term RCT to be conducted in Maryland and Nevada ensuring sites that will be inclusive and representative of diverse populations. Our long-term goal is to eliminate pain care disparities and reduce our society’s reliance on opioids to manage pain. Leveraging technology, the proposed study will help advance mAPA, a novel, easy-to-initiate, rapid, safe, and non-pharmacological tool incorporated in a self-management plan to habitually manage pain in real-world settings.