The current study investigates the theory of planned behavior with important additional predictors from the social identity approach. The study explores whether social identity might function as a driver of the theory of planned behavior and help explain how abstract group processes might impact student binge drinking behavior. Adopting a controlled statistical analysis, the hypothesized model expands the theory of planned behavior's current conceptualization of group norms and considers how the behavioral content of a specific group, with group identification, impacts binge drinking behavior (N = 551 university students). A path analysis that simultaneously mapped all the hypothesized relationships supported a reconceptualization of social identity as a predictor within the theory of planned behavior. The interaction between group identification and the importance of drinking to the group's identity significantly predicted an individual's attitudes towards binge drinking and perceived social binge drinking norms (subjective, descriptive and injunctive), which in turn predicted intentions to binge drink. Intentions to binge drink predicted self-reported binge drinking behavior two weeks later, above and beyond relevant covariates. The implications of these findings are discussed, with recommendations for future research.