SUMMARY/ABSTRACT: Community Engagement, Recruitment, and Retention Core D The Community Engagement, Recruitment and Retention (CERR) Core will design, implement and evaluate innovative and effective strategies for community engagement, recruitment, and retention of participants in the Precision Aging Network (PAN). Using social media and evidence-based community engagement strategies, the CERR Core will launch a campaign that will enable the recruitment of a large and diverse cohort (Project 1, MC-Catchment, 350,000 individuals) for internet-based assessments. 100,000 of these participants will be recruited into an expanded study that includes additional cognitive testing and survey questions (Project 1, MC-Expanded). The CERR Core will facilitate the efforts required for the recruitment and retention into this aspect as well. Additionally, the CERR Core will work with Project 2 to recruit and retain participants in four geographic locations – Tucson, Baltimore, Atlanta, and Miami – for extensive in-person assessments (Project 2, 1,620 individuals). The CERR Core will use virtual and in-person approaches to retain a multiethnic longitudinal cohort (n = 50,000 for Project 1, MC-Longitudinal) and a diverse cohort (n = 1000 for Project 2-Longitudinal). The CERR Core will monitor and evaluate outcomes from different approaches to optimize methods for recruiting underrepresented groups in human health studies. The CERR Core will use culturally-optimized methods to develop a national campaign, partnering with community advisory boards and stakeholders, to support the long-term goals of the PAN and the specific aims of the Projects in this application. We will also increase community awareness regarding the science of cognitive aging, Alzheimer’s disease (AD), and AD-related dementias (ADRD) by engaging the community, our partners, and the next generation of researchers including student ambassadors. In this way, the CERR Core will contribute to the advancement of cognitive aging and dementia research by increasing participation of under-represented populations in one of the largest U.S. cohort studies ever created.