The Health and Retirement Study (HRS) is a longitudinal panel study that has surveyed a representative sample of approximately 20,000 people over age 50 in America every two years since 1992. The HRS is supported by the National Institute on Aging (NIA U01AG009740) and the Social Security Administration. Through its unique and in-depth interviews, the HRS provides an invaluable and growing body of free multidisciplinary data that researchers can use to address important questions about the challenges and opportunities of aging. Innovation in survey design and content is a hallmark of the HRS. In addition to core survey content on health and health insurance, employment and retirement, income and wealth, and family connections, HRS data includes psychosocial functioning, genetics, physical performance, and venous blood for biomarkers. In addition, HRS has contributed to building an infrastructure for cross national comparisons by serving as the model for a network of studies of aging around the world with harmonized content. Leveraging this infrastructure, the HRS launched the Harmonized Cognitive Assessment Protocol (HCAP) in 2016, collaborating and harmonizing with multiple international partners to establish an international data resource to better understand and compare the causes, consequences, and trends in dementia in the U.S. and around the world. HRS data has served as the foundation for over 3,900 peer-reviewed journal articles by over 7,400 different authors and co-authors. Over 800 graduate students have based their Master's thesis or PhD dissertation on HRS data, and the data has also supported more than 1000 working papers and 200 books.