PROJECT SUMMARY The Covid-19 pandemic has had a substantial impact on vulnerable aging populations across the world. Clinical care of patients with Alzheimer’s associated dementia are especially vulnerable to the effects of Covid- 19 and Covid-19 has been associated with poor outcomes in patients. In this National Alzheimer’s Coordinating Center (NACC) Administrative Supplement proposal, we are providing the infrastructure for investigating the genetic factors associated with poor outcomes in patients with AD and a history of Covid-19. We are leveraging and deploying new data collection instruments for Covid-19 phenotypes to the Alzheimer’s Disease Research Centers Consortium (ADRCs). This work will provide a high impact, innovative, and economical demonstration of the use of routine clinical care data to quantitatively and accurately phenotype patients. Care data in the form of Centers for Medicare and Medicaid Services (CMS) administrative claims and electronic health record (EHR) will be the basis for this demonstration. NACC will collaborate with NIAGADS and three pilot sites, Washington University St. Louis, Columbia University and Indiana University ADRCs. This work will be done in three aims. First, we will support additional clinical research at the pilot clinical sites and will deploy new prospective data collection instruments to support post acute sequelae of Covid-19. Second, we will assess feasibility of and begin to collect EHR and CMS data in partnership with the ADRC pilot sites and the NIA. Finally, we will collaborate with NIAGADS to enable collaborative analysis of integrated phenotype and genetic data of enrolled participant data. Together this proposal, if funded, will place important infrastructure for the study of AD associated phenotypes and Covid-19.