To effectively address disparities in addiction and pain research, a shared understanding of the determinants that impact equitable implementation across different populations is needed. This project aims to develop a taxonomy that maps and describes factors related to equity in addiction and pain implementation research. The taxonomy will be built by drawing on two existing implementation frameworks (Consolidated Framework for Implementation Research [CFIR]; Health Equity Implementation Framework [HEIF]), conducting a scoping review, and collecting feedback from RASC domain experts. Dr. Sawyer-Morris will quantitatively validate the taxonomy using topic modeling (i.e., unsupervised machine learning) to uncover key topics/themes in a subset of HEAL research abstracts (i.e., projects that address underserved populations). Results will be used to further refine the taxonomy, and inform the development of a centralized public use product for assessing equity determinants in implementation research.