The Health and Medical Care Archive (HMCA) is the data archive of the Robert Wood Johnson Foundation (RWJF), the largest philanthropy devoted exclusively to health and health care in the United States. Operated by the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan with funding from RWJF, HMCA preserves and disseminates data collected by selected research projects funded by RWJF and facilitates secondary analyses of the data. The data collections in HMCA primarily includes large-scale surveys of the American public about public health, attitudes towards health reform, and access to medical care; surveys of health care professionals and organizations, public health professionals, and nurses; evaluations of innovative programs for the delivery of health care, and many other topics and populations of interest. Our goal is to build a culture of health by increasing the understanding of health and health care and the factors that contribute to health in the United States through secondary analysis of RWJF-supported data collections.