Although teams of negotiators are widely assumed to be better at unlocking integrative solutions than individual negotiators, the interteam negotiation context is characterized by unique challenges which can make effective collaboration between teams difficult. The authors extend their theoretical understanding of interteam negotiations by offering novel insights about when and why teams realize their potential in integrative negotiations. Specifically, they propose a theoretical model that explains how hierarchical team structures reduce information elaboration within teams, which reinforces “fixed-pie” assumptions that prompt the reliance on value claiming behaviors between teams and lower high-quality outcomes such as the joint gain achieved. Across four studies, each involving interactive team-on-team negotiations, the authors provide support for the hypothesized effects of formal intrateam hierarchies on joint gain, and test a useful intervention to mitigate the harmful effects of hierarchically structured teams at the negotiation table. Contributions to the literatures on team negotiations, interteam collaboration, and hierarchical differences within teams are discussed.