The purpose of this limited competition FOA is to allow the Biomarkers for Older Control at Risk for Dementia (BIOCARD) investigators to submit a continuation application for another 5 year funding period, providing for resubmission and possible future revision applications. This is a uniquely valuable cohort of individuals at high risk for developing AD, many of whom have already developed early signs of dementia. There is almost 20 years of repeated clinical evaluations, neuropsychological testing, and plasma samples, as well as 15 years of structural MRI data and CSF samples. Revision applications may not request support beyond the project end date of the Parent U19 award.