PROJECT SUMMARY The Health and Retirement Study (HRS) is the premier data set worldwide for the study of aging in all its complexities. The RAND HRS Longitudinal File and its supplementary files, that constitute the RAND HRS Data System, have been instrumental in facilitating the use of the HRS in the work of thousands of researchers in the U.S. and around the world. This project will substantially expand the RAND HRS Data System to realize the full potential of the HRS and to facilitate rigorous multidisciplinary research on health and aging. We propose to create innovative summary measures and improve upon existing ones. One main effort will be to create indices of high-level concepts such as health and disability, psycho-social construct variables, and subjective well-being and to develop estimates of pension and Social Security wealth. We will develop these measures involving experts so as to provide researchers in one discipline with state-of-knowledge measures from other disciplines, thus encouraging transdisciplinary research. A second effort will be to develop new data products such as a longitudinal Respondent-Parent file and Respondent-Helper files to advance research on long-term care. We would investigate the feasibility of a restricted data file that would incorporate variables derived from administrative Social Security data. We will improve the derivation of a number of existing variables in the RAND HRS and maintain and update all supplementary data products and new data elements as additional waves of HRS data become available. This will be a collaborative effort between the HRS and the RAND HRS teams. The HRS team will bring the scientific expertise of the HRS Co-Investigators to the development of new data elements that can be used across all disciplines. The RAND team will bring methodological and technical skills and over twenty years of experience in programming using the HRS data. The proposed expansion of the content of the RAND HRS Data System requires innovative use of the rich and complex original HRS data. We will develop data elements using rigorous, systematic methods in consultation with experts, with focus on longitudinal consistency. The new data elements in the expanded and improved RAND HRS Data System will strengthen an important data infrastructure and will facilitate downstream high-quality multidisciplinary research in high- priority areas of NIA in health and aging, including, for example, investigations of disparities in health and subjective well-being, the personal, interpersonal and societal causes of physical and mental health at older ages, the burden of caregiving on family members, and disparities in the use and provision of informal care. With the availability of the expanded RAND HRS Data System, researchers will be able to more rapidly address new and evolving issues and challenges facing burgeoning older populations, including their care, financial, and health needs.