Abstract Building resources to make data from high value, publicly funded cohort studies widely accessible, (re)usable, and interoperable is one of the National Institute on Aging's key milestones of the Alzheimer's Disease and Related Dementia (AD/ADRD) research implementation. The Gateway to Global Aging Data is a data platform developed to harmonize and disseminate data from the Health and Retirement Study and its international network of studies (HRS-INS) to facilitate longitudinal analyses on aging across 47 countries. Expanding on an already successful platform, this application aims to bring in newly available data on late-life cognition and dementia, collected using the Harmonized Cognitive Assessment Protocol (HCAP), together with other newly available data from core longitudinal interviews, self-completion questionnaire, Life-History interviews, End-of-Life interviews, and the special COVID-19 surveys, to promote high-quality studies of late- life cognition, mild cognitive impairment (MCI), and AD/ADRD. We will also integrate contextual data, specifically, air pollution exposures, institutional and policy measures related to long-term care and end-of-life care, and information about the COVID-19 pandemic. Air pollution is a modifiable risk factor for AD/ADRD yet most research is from individual countries and focused on total particulate pollution. By newly estimating air pollution from different sources at respondent addresses, we will enable interested researchers to investigate the effects of exposures on cognitive decline, MCI, and AD/ADRD, across multiple countries. Similarly, the utilization, cost, and quality of long-term care related to dementia are emerging areas of concern. Thus, we aim to identify institutional and policy differences in formal long-term, informal, end-of-life, and dementia care for the respondents of the HRS-INS. Finally, the COVID-19 pandemic has been devastating to older adults though the full magnitude of its impacts has yet to be understood. Survey data from the HRS-INS can inform the extent of the damage. As we grow our database with new measures and expand our user base, we seek to redesign the technical implementation of our metadata extraction, contextual data integration, and data management and dissemination application. Such investment in data infrastructure is justified when the data are widely used to produce novel and meaningful new knowledge, insights on population health, including AD/ADRD and dementia care, and ultimately policy innovations. To facilitate the widespread use of the Gateway's resources, we will further strengthen user training and support by regularly organizing user conferences and workshops in addition to our regularly scheduled webinars. By amassing this expansive platform of high-quality information from the HRS-INS harmonized by subject-area experts, making these data publically available, and conducting outreach to support use of these data, we anticipate that the Gateway ...