Cohabitation has become part of the pathway toward marriage. Prior work focuses on expectations to marry and has ignored cohabitation. Although most young adults are not replacing marriage with cohabitation, but instead cohabit and then marry, it is important to study adolescents’ joint expectations to cohabit as well as marry. Our analyses draw on recently collected data from the Toledo Adolescent Relationships Study (N = 1,293). We find that adolescents are less certain about their cohabitation than marriage expectations. Dating and sexual experience, traditional values, prosocial activities, and parents influence adolescents’ union formation expectations. The findings from this work suggest that adolescents are including cohabitation as part of their future life trajectories but rarely envision cohabitation as substituting for marriage.