Teams with an indefinite lifespan must adapt regularly to member turnover. Changes in team membership present a management challenge for ongoing action teams that perform complex, interdependent tasks because members must quickly learn new ways of working together. We examined how changes in a team’s composition affect team performance in professional hockey teams in the National Hockey League. With data spanning 10 seasons we assessed how team quality (quality and variation in members’ and leaders’ knowledge, skills, and abilities) and team continuity (member and leader turnover) affect team performance. Results suggest that team member and leader characteristics have both additive and interactive effects on team performance. We discuss the implications of team composition as a mechanism for accelerating team development and performance in teams with regular member turnover.