Past good deeds can liberate individuals to engage in behaviors that are immoral, unethical, or otherwise problematic, behaviors that they would otherwise avoid for fear of feeling or appearing immoral. We review research on this moral self-licensing effect in the domains of political correctness, prosocial behavior, and consumer choice. We also discuss remaining theoretical tensions in the literature: Do good deeds reframe bad deeds (moral credentials) or merely balance them out (moral credits)? When does past behavior liberate and when does it constrain? Is self-licensing primarily for others’ benefit (self-presentational) or is it also a way for people to reassure themselves that they are moral people? Finally, we propose avenues for future research that could begin to address these unanswered questions.