Summary The overall goal of this project is to provide a scientific understanding of the heterogeneous outcomes of recovery from opioid use disorder (OUD). Toward this end, this project will demonstrate that (1) latent factors important to recovery from OUD exist, (2) subgroups explain the heterogeneity among individuals in recovery from OUD, (3) individuals transition among these subgroups during their recovery process, (4) individual-level factors are pre- dictive of subgroup transitions, and (5) changes in latent recovery factors are associated with recovery outcomes. To accomplish these objectives, this project will develop novel statistical methodologies to identify subgroups of individuals in, and the latent recovery factors necessary to achieve, recovery from OUD. To succeed, the com- bined expertise of the research team in statistical method development, psychosocial data analysis, and recovery from substance use disorders, including OUD, will be leveraged. All analyses will be performed on the Remission from Chronic Opioid Use–Studying Environmental and Socioeconomic Factors on Recovery (RECOVER) Study, a longitudinal study of individuals who received subcutaneous buprenorphine injections for OUD treatment. The RECOVER data set assessed psychosocial measures including depression, life stress, pain, withdrawal, and quality of life during four years of recovery. In Aim 1, a novel Bayesian Dynamic Clustering Factor Model (BD- CFM) will be developed. These latent factors will then be used to identify subgroups of individuals, and changes in individual-level psychosocial factors that are precipitants of transitions among these subgroups. In Aim 2, an extension of the BDCFM will be developed to identify changes in latent recovery factors as predictors of recovery outcomes, such as re-initiation of opioid use (i.e., relapse) and treatment utilization. Overall, this project is highly innovative and impactful as it will provide a deeper understanding of the heterogeneity of recovery from OUD, and thereby informing subgroup specific interventions to facilitate successful recovery.