In this paper, we introduce the Team Effectiveness Model for Science (TEMS) and describe a multiphase set of interventions for forming a new team or developing an existing team. TEMS uses a shared mutual learning mindset as the model’s central and guiding element. It shows how team mindset leads to behavior and to results and how this affects the characteristics of effective team functioning. TEMS addresses two related questions: What are the variables that contribute to effective teams? and How do the variables need to be designed to make their relevant contributions? Team models often answer the first question without fully answering the second. By addressing three gaps, TEMS contributes to enhancing science team effectiveness. Gap 1 is the absence of explicit core values, assumptions, and norms that serve as the foundation for developing and maintaining science team effectiveness. Gap 2 is the absence of a process for integrating the science and relationship aspects of a science team. Gap 3 is the absence of team processes and structures that are derived from the team’s values, assumptions, and norms. Using TEMS to design new or intervene with existing teams focuses on shifting mindset, developing behavioral skills, and designing processes and structures congruent with the new mindset.