The Robert Wood Johnson Foundation (RWJF) is focused on building a national Culture of Health. A Culture of Health is one where all are enabled to lead healthier lives, now and for generations to come. The Foundation believes deeply in the importance of research, evaluation, and learning to build a transdisciplinary evidence base that helps inform efforts to improve health, well-being, and equity. They recognize that access to rich data is a cornerstone of producing such timely and objective research. Health Data for Action (HD4A), the newest RWJF signature research program, aims to reduce the barriers often faced in accessing rich data by serving as a conduit between data owners and interested researchers. Through each HD4A funding opportunity, RWJF will make valuable data from unique data owners available to researchers.