Cultural context can affect how changes in self-concepts are either valued or tolerated. However, very little is currently known regarding how culture may differentially confer consequences to people that change their self-concepts over the course of several years. We investigated the moderating role of culture (Japan and USA) on the link between long-term (∼4 years) self-concept changes and a comprehensive set of well-being measures (hedonic, eudaimonic, and family based). We found that American’s self-concept instability was more negatively associated with one’s well-being and emotional support within one’s family than Japanese. Furthermore, Americans were particularly negatively impacted when they became less agentic and conscientious over time. One possible interpretation is that Western, individualistic cultures may discourage people from changing their identities throughout their adult life. Although American culture often espouses the sanctity of freedom, American culture may also limit people’s freedom to change how they see themselves over time.