Growing evidence documents strong associations between volunteering and favorable health and well-being outcomes. However, epidemiological studies have not evaluated whether changes in volunteering are associated with subsequent health and well-being outcomes. Data were from 12,998 participants in the Health and Retirement Study-a large, diverse, prospective, and nationally representative cohort of U.S. adults aged >50 years. Using multiple logistic, linear, and generalized linear regression models, this study evaluated if changes in volunteering (between t0, 2006/2008 and t1, 2010/2012) were associated with 34 indicators of physical health, health behaviors, and psychosocial well-being (in t2, 2014/2016). Models adjusted for sociodemographics, physical health, health behaviors, psychosocial factors, and personality, as well as volunteering and all outcomes in the prebaseline wave (t0, 2006/2008). Results accounted for multiple testing and data were analyzed in 2019. During the 4-year follow-up period, participants who volunteered ≥100 hours/year (versus 0 hours/year) had a reduced risk of mortality and physical functioning limitations, higher physical activity, and better psychosocial outcomes (higher: positive affect, optimism, and purpose in life; lower: depressive symptoms, hopelessness, loneliness, and infrequent contact with friends). Volunteering was not associated with other physical health outcomes (diabetes, hypertension, stroke, cancer, heart disease, lung disease, arthritis, overweight/obesity, cognitive impairment, and chronic pain), health behaviors (binge drinking, smoking, and sleep problems), or psychosocial outcomes (life satisfaction, mastery, health/financial mastery, depression, negative affect, perceived constraints, and contact with other family/children). With further research, volunteering is an activity that physicians might suggest to their willing and able patients as a way of simultaneously enhancing health and society.