Exploring the direct predictors of employee green behavior (EGB) has been a central issue for achieving organizational sustainability. According to the ability, motivation, and opportunity (AMO) theory, it is the employee ability-motivation-opportunity configuration that yields behavior and performance. However, how the three dimensions interact to produce EGB remains unclear. Far too little attention has been given to individual heterogeneity in motivation within the AMO framework. By integrating the AMO framework and regulatory focus theory, we explore the A-M-O configurations that are sufficient for the presence of EGB in the Chinese context, including required green behavior (RGB) and voluntary green behavior (VGB). Adopting fuzzy-set qualitative comparative analysis (fsQCA), we find two configurations leading to RGB and three configurations that are sufficient to yield VGB. Specifically, prevention-focused employees with green self-efficacy and high-quality supervisor-subordinate guanxi (SSG) tend to perform more RGB. Green autonomy is essential for the VGB of promotion-focused employees, while green self-efficacy and SSG are alternatives. In particular, employees motivated by both a promotion and prevention focus are prone to strike a balance between RGB and VGB. Accordingly, they need more resources to support their ambidexterity. Finally, we discuss the theoretical contributions and managerial implications of this study.