Project Summary The MACS WIHS Combined Cohort Study (MWCCS) is the largest ongoing longitudinal cohort study of adults living with and without HIV. To date, the MWCCS has followed more than 13,828 unique participants and collected data at 285,840 person-visits over a 40-year period. This study has generated a large body of high-dimensional data including clinical, behavioral, social, genomic, and metabolomic. These data have led to more than 3000 peer-reviewed publications and are in high demand by investigators. Despite extensive documentation of the data, given their complexity, it can be challenging for investigators to understand what data is available for use. Therefore, efforts to make the MWCCS data more discoverable to investigators would be valuable and are aligned with the mission of the MWCCS Data Analysis and Coordinating Center (DACC). The goal of this proposal is to engage with the team at GO FAIR US to make the MWCCS data more discoverable to investigators and more interoperable with the NIAID data environment and other repositories across multiple platforms. We aim to 1) provide standardized metadata to share with the NIAID Data Ecosystem Discovery Portal, 2) develop aggregate-level count tables to populate a basic data dashboard, and 3) plan technologic feasibility for future data visiting of study data.