Teams often engage in too little planning and initiate action too quickly. Agile work practices try to correct this “action bias” by letting team members complete their tasks in iterative goal cycles (agile taskwork) and conducting frequent coordination meetings (agile teamwork). While this combination of taskwork and teamwork practices can enable teams to develop useful solutions in short timeframes, it may go at the cost of novelty and future-focused action. The present study proposes that the combination of agile taskwork and agile teamwork shifts attention from doing to planning, which can undermine team proactivity. We find support for this taskwork-teamwork interaction effect in a time-lagged study of 71 agile teams of a large German organization with two measurement moments separated by one year. Teams that approached tasks in iterative goal cycles (high agile taskwork) were more proactive one year later, which allowed them to realize improvements in team performance. However, this positive effect was attenuated when teams conducted frequent coordination meetings (high agile teamwork). We conclude that teams must find the right balance of planning and doing, to proactively improve their performance. This study builds new theory on agile teams and contributes to a more nuanced understanding of team planning and proactivity.