In today's organizations, employees are often assigned as members of multiple teams simultaneously (i.e., multiple team membership), and yet we know little about important leadership and employee phenomena in such settings. Using a scenario-based experiment and 2 field studies of leaders and their employees in the People's Republic of China and the United States, we examined how empowering leadership exhibited by 2 different team leaders toward a single employee working on 2 different teams can spillover to affect that employee's psychological empowerment and subsequent proactivity across teams. Consistent across all 3 studies, we found that each of the team leaders' empowering leadership uniquely and positively influenced an employee's psychological empowerment and subsequent proactive behaviors. In the field studies, we further found that empowering leadership exhibited by one team leader influenced the psychological empowerment and proactive behaviors of their team member not only in that leader's team but also in the other team outside of that leader's stewardship. Finally, across studies, we found that empowering leadership exhibited on one team can substitute for lower levels of empowering leadership experienced in a different team led by a distinct leader. We discuss our contributions to the motivation, teams, and leadership literatures and provide practical guidance for leaders charged with managing employees that have multiple team memberships. (PsycINFO Database Record (c) 2019 APA, all rights reserved).