PROJECT SUMMARY/ABSTRACT The US National Plan for AD (National Alzheimer's Project Act, NAPA) has the ambitious goal of preventing and effectively treating Alzheimer’s disease (AD) by 2025 through the support of innovative research focused on AD etiology, early detection, and therapeutics. The National Centralized Repository for Alzheimer’s Disease and Related Dementias (NCRAD) is an NIA-funded Cooperative Agreement that serves as the primary resource for sample sharing for all NIA-funded Alzheimer’s disease and related dementias (ADRD) studies. This application is in response to a request by NIA to continue the support for NCRAD (RFA-AG-21-005). Over the past 30 years, NCRAD has exceeded its goals for sample storage and sample distribution, and thereby significantly facilitated ADRD research progress. Over the next five years, NCRAD will work closely with NIA and other national efforts in ADRD research to advance genomic and biomarker efforts aimed at identifying those at greatest risk for ADRD and to delay and prevent ADRD. To achieve these key goals, NCRAD will pursue the following specific aims: Aim 1: Provide a state-of-the-art central biospecimen repository for all NIA-funded dementia studies. 1.1 Provide study-specific biospecimen management. 1.2 Ensure comprehensive specimen quality. 1.3 Receive and expand ADRD-related cell lines for distribution to the research community. Aim 2: Facilitate and foster sample sharing to all qualified investigators. 2.1 Maximize the value of samples at NCRAD. 2.2 Develop user-friendly approaches to promote and review NCRAD resources. 2.3 Distribute samples to (approved) researchers.