Studies of the effects of top management team (TMT) composition on organizational outcomes have yielded mixed and confusing results. A possible breakthrough resides in the reality that TMTs vary in how they are fundamentally structured. Some are structured such that members operate independently of each other, while others are set up such that roles are highly interdependent. We examine the potential for three facets of structural interdependence—horizontal, vertical, and reward interdependence—to resolve ambiguities regarding effects of TMT heterogeneity. Based on a sample of TMTs in technology firms, we find that the three facets of structural interdependence are potent moderators of two classic predictions: the positive association between TMT heterogeneity and member departures, and between TMT heterogeneity and firm performance. Copyright © 2014 John Wiley & Sons, Ltd.