Group member change or team stability is a popular and important topic in the group and organizational behavior literature. Team member stability is viewed as a critical factor for an effectively functioning and performing group. Even though there is a plethora of studies on group member change and stability, research on member stability in cross-functional new product development teams is still lacking. This study explores the antecedent factors that impact new product development team stability as well as its consequences. By studying 211 new product teams, we found: (1) the most direct antecedents of team stability are goal stability and goal support; and (2) team stability has a significantly positive effect on outcome variables including team learning and cycle time. This study also shows that team stability may not be universally good; under some circumstances, such as when there is a high degree of market and technical turbulence, team instability can be advantageous. (C) 2002 Elsevier Science B.V. All rights reserved.