One important aspect of social competence is the ability to accommodate social behavior to different contexts. Can children who are just beginning to acquire peer interactional skills adjust their social behavior to the age of their partner? 18- and 24-month-old children were paired in same-age or mixed-age dyads, and their spontaneously occurring peer interactions were observed. Previously documented age differences in peer skills were replicated. Additionally, toddlers in mixed-age dyads adjusted both the behavioral content and the complexity of their social behavior to the age of their partners. For initiations the effects were interactive. That is, children's adjustments in social behavior were a function of both the child's age and the partner's age. There also were age-related constraints on the accommodations that children made to one another. Speculations are offered about potential contributions to these developments during the second year. Results support arguments for the uniqueness of the mixed-age context, and show that by the second year children possess rudimentary skills to permit functional accommodations to this context.