The Clinical Core (CC) will enroll participants in a carefully considered cohort to with a primary goal in the P20 phase of demonstrating the feasibility of collecting the proposed dataset from a cohort with substantial representation of groups disparately affected by Alzheimer?s disease and related dementias (ADRD) in the Deep South, and establishing the capacity to perform all critical Clinical Core functions. Projected enrollment will include 50 new participants annually for 3 years. The cohort will include cognitively unimpaired (~50%), MCI (~30%) and mild dementia (~20%). Black or African American (B/AA) participants will be over- represented in the cohort, working closely with the Community Outreach, Diversity, and Inclusion Core. The Core will collect the uniform dataset, several other cognitive and functional measures, and evaluation of social determinants of health and vascular risks. Fluid biomarkers including blood and urine will be collected from all participants, with CSF optional but encouraged. Genotyping from blood samples will be conducted with colleagues in the UAB-HudsonAlpha Center for Genomic Medicine and shared via NIAGADS. CSF, blood products, and urine will be banked for local access and shared via NCRAD. A subset of participants will receive neuroimaging, which includes structural and functional MRI, [11C]PiB amyloid PET, and [18F]flortaucipir Tau PET. A multidisciplinary Clinical Consensus Conference will determine diagnostic clinical classifications. A separate Biomarker Consensus Conference will classify individuals to A/T/N categories while blinded to the clinical data and classification. Data from sequential clinical assessments will be collected and submitted to NACC per UDS protocols. Well-characterized participants will be referred to clinical investigators approved via the ADRC?s Data Sharing and Protocol Review process. Pre-mortem autopsy coordination and consent, as well as longitudinal assessment data will be collected on behalf of the brain donation program.