Integrating the social norm perspective and regulatory focus theory, this research expands the current understanding of how and why (in)congruence modes between supervisor prescriptive and descriptive norms shape voluntary and required employee green behaviors (EGBs) through a regulatory focus process. It tests a proposed model with two independent studies: an experiment manipulating both supervisor prescriptive and descriptive norms of EGB (US tourism and hospitality employees in Study 1) and a field survey study measuring both supervisor-reported prescriptive and descriptive norms of EGB (Chinese hospitality employees in Study 2). Results reveal that the congruence/incongruence between supervisor prescriptive and descriptive norms of EGB has a positive relationship on voluntary/required EGB through employee promotion/prevention focus of EGB, respectively. This research provides more nuanced understandings into the psychological mechanism that explains how the self-regulatory focus of EGB mediates the interactive influences of supervisor prescriptive and descriptive norms of EGB on voluntary and required EGBs.