Adverse childhood experiences (ACEs) reflect stressful or traumatic early life events such as abuse, neglect, and significant household challenges. These experiences are increasingly appreciated as factors that exert influence on physical and mental functioning throughout the lifespan. Numerous studies have demonstrated dose–response relationships between the number of ACEs reported and negative health outcomes in adulthood (Anda et al., 2006). At the same time, evidence points to the role of ACEs in the development of heightened biological reactivity to stress that may serve to increase vulnerability to the development of mental and substance use disorders (e.g., Heim et al., 2010). Furthermore, the existence of sex differences in both stress reactivity and the prevalence of various forms of psychopathology in adulthood (Doom et al., 2013) raises the question of whether men and women are differentially vulnerable to the health risks posed by ACEs. Much of the work concerning ACEs has focused on outcomes as they present in middle adulthood, which may not generalize to later life, as there may be cohort effects in the prevalence of (or likelihood of reporting) ACEs. Studies finding that the newly old report greater numbers of ACEs than their more senior counterparts imply that rates of ACEs are increasing over time and may be contributing to the development of mental and substance abuse disorders (MSUDs) in the growing population of aging adults, and make a case for better understanding these associations in later life.