ABSTRACT - RESOURCE CORE The American Joint Replacement Registry (AJRR) is part of the American Academy of Orthopedic Surgeons (AAOS) Registry Program and is the Resource Core of the American Joint Replacement Research- Collaborative (AJRR-C). The AJRR currently includes >1,200 participating institutions and captures about 25- 30% of all hip and knee TJA procedures in the United States. The AJRR enhances the clinical research capabilities of the TJA research community by providing access to nationwide shared data resources and implementing novel data collection, data analysis methodologies and study designs to facilitate TJA research in large-linked databases and clinical research networks. The Specific Aims of the Resource Core are: (1) To work collaboratively with the AJRR-C Methodology Core in design, protocol development, statistical analysis and conduct of TJA studies, (2) To test the transportability and external validity of TJA-specific validation and artificial intelligence (AI) algorithms (developed by the Methodology Core) in hospitals within the AJRR network in an effort to improve the depth and completeness of the registry data, and (3) To participate in pilot & feasibility studies within the AJRR-C network and to develop analytical standards for use of AJRR data in partnership with academic and community-based institutions. We will focus on high-priority areas such as risk adjustment when comparing implants and classes of implants, and use state-of-the-art and novel statistical methods to evaluate new TJA technologies. The availability of implant- specific data from the AJRR, enriched with linked databases and EHR data sources offer tremendous research opportunities and will exert a sustained, powerful influence on TJA clinical research landscape and device surveillance.