ABSTRACT Chronic low back pain (cLBP) affects over 10% of adults in the US, contributing to significant disability, substantial health care costs, and increasing the risk of opioid addiction or overdose for those suffering with cLBP. The NIH Back Pain Consortium (BACPAC), a key component of the NIH Helping to End Addiction Long- TermSM (HEAL) Initiative, is comprised of leading centers with expertise in the pathogenesis and treatment of cLBP. The Back Pain Consortium was assembled to advance understanding of the mechanisms that underlie cLBP as well as to identify novel treatments and treatment strategies for cLBP. Currently, there are a number of evidence-based treatments for low back pain that have been demonstrated to have modest effect sizes on average, but there is a dearth of guidance for clinicians regarding which treatments are best studied for specific patients based on the patient's own phenotypic characteristics. Accordingly, BACPAC is undertaking a large, multi-site, sequential, multiple assignment randomized trial (SMART) that will use existing and novel technologies to phenotype individuals experiencing cLBP. The primary objective of this trial is to estimate optimal precision medicine algorithms (i.e., dynamic treatment regimes) to assist clinicians in making treatment recommendations for future patients. The trial will evaluate a complementary set of treatments, including physical therapy, medication (duloxetine), enhanced self-care, and acceptance and commitment therapy, each of which may be used alone or to augment an existing treatment plan. Having racial, ethnic, and socioeconomic diversity of participants enrolled in this trial is crucial to our ability to learn optimal treatment strategies for individual patients and to ensure that what is learned is applicable to all individuals living with cLBP in the United States (US). This project aims to comprehensively address the challenges of recruiting and retaining a diverse population of cLBP patients that is reflective of the population of individuals who live with cLBP in the US. Through development of comprehensive recruitment and retention plans for strategically chosen study sites that have the capability to recruit from underrepresented populations (e.g., Black and Hispanic populations), and by providing dedicated financial resources to engage patients from these populations using tailored, culturally appropriate strategies, this first-in-kind precision medicine trial can provide unique insight into how we can better treat all cLBP patients, including those from racially and ethnically diverse backgrounds that have historically been excluded from clinical research.