The recent development of epigenetic “clocks” is creating new opportunities to understand why individuals vary in the pace of health and functional decline with age. With support with a 5-year NIH R01 grant, we are currently re-contacting all cohort members and their mothers to update key survey information, obtain biological samples for epigenetic and biomarker assessment, and to update mortality information. We will use these data, along with the 40 years of longitudinal data available for each birth cohort member, to clarify the role of early life factors as predictors of epigenetic age in early adulthood and the lifestyle and other factors that influence the pace of change in epigenetic age across a 17 year period of follow up. In addition, we will use baseline epigenetic clock data to understand what influences the subsequent pace of decline in health, biological function and mortality among the older, mothers’ generation. Data on these generations is thus allowing us to study the aging process from birth to old age decline and mortality, focusing on both the developmental and lifelong determinants of epigenetic age and the aging-related outcomes that epigenetic age predicts late in life.