This study examined the impact of informational attributes of team membership change on affective emergent states and team effectiveness, and how members’ emotional intelligence (EI) shapes this impact. Results from two laboratory studies showed that change predictability and rationality affected team potency and identification. These emergent states had unique effects on team effectiveness over and above the effects of team process. Results also showed that members’ EI moderated the effects of change predictability and rationality. These findings emphasize the importance of membership change attributes, affective emergent states, and team composition in determining team effectiveness after a membership change.