[Excerpt] Teams pervade today’s organizations. As boundaries become increasingly permeable, recurring changes in team memberships – some planned and some unplanned – are inevitable. Yet, frequent transitions of talent in and out of teams can be unnerving; no one knows for sure how the changes will affect the teams or their members until the dust settles. What can organizations do to ease the uncertainty and anxiety, while keeping team members focused on their collective tasks? We know from research on broad organizational change that communication is always critical. But what messages really matter when the issue is changes in team memberships? And why?