By emerging adulthood, the majority of individuals have engaged in some types of sexual behavior. However, during this period there is considerable variability and change in the prevalence of recent sexual behaviors and their relationship contexts. This chapter reviews the literature on the prevalence of multiple sexual behaviors, focusing on data from nationally representative studies where possible. Findings suggest that most emerging adults engage in behaviors such as kissing, oral sex, and vaginal intercourse during emerging adulthood, with peak prevalence of these behaviors in the late twenties or early thirties. Other behaviors, such as partnered masturbation, anal sex, and kink behaviors are also practiced by a sizeable minority of individuals. Although many individuals engage in casual sex during emerging adulthood, most instances of sexual behavior occur in relationships. Differences in sexual behavior across several subgroups are discussed, with a particular focus on gender and sexual orientation.