SummaryWe developed and tested a model that bridges existing team effectiveness theory with new ideas aimed at understanding the complexity of multiple team membership and virtuality. Using a sample of 60 global, virtual supply teams from a large multi-national organization, we propose that even for new team configurations, transactive memory systems and preparation activities are critical for effectiveness. We also examined the association between members' percentage of time allocated to a team, team virtuality, and interdependence on preparation activities. Our findings suggest that preparation activities related significantly to effectiveness as mediated by transactive memory systems. Furthermore, interdependence interacted with members' percentage of time allocated to the team as related to preparation activities. Specifically, members' percentage of time allocated to the team shifted from being a positive influence on preparation activities to a negative influence as team interdependence went from relatively high to relatively low levels. We discuss implications for theory, research, and practice. The simple fact is that team arrangements suitable for IPO-style investigations may be more the exception than the rule in modern-day organizations. Therefore, our challenge for future researchers is to embrace the complexity of current team arrangements. Rather than viewing the complex features of organizational teams as confounds or design problems to overcome, we submit that they are important variances to assess, model, and understand (p. 463).Similarly, the call for this special issue of the Journal of Organizational Behavior submitted the following: "changes in communications technology, organizational purposes, and the social dynamics of new generations of young professionals are together leading to the emergence of new kinds of teams in organizational life." With team phenomena starting to look significantly different, we propose to expand what we know about the antecedents, mediators, and outcomes of today's complex, dynamic teams by developing and testing a model that bridges what we "know" about teams, with newer practices emerging in organizations. Even though what teams look like has changed dramatically over the last decade, teams are still used to perform organizationally relevant tasks. Consequently, we submit that it is important not to disregard what we know about traditional teams but rather to leverage the lessons learned from prior research while simultaneously incorporating the complexity of modern-day arrangements into models of team effectiveness.