Collaborative school reforms and teacher evaluation reforms both show promise for improving teaching and learning in American schools. However, these reform movements have largely been implemented separately from each other, and because they are predicated on very different assumptions about how schools and teachers contribute to student learning, they have the potential to undermine each other. Therefore, the purpose of this article is to begin conceptualizing one avenue for reconciling these policies: developing measures to evaluate collaborative teaching. Drawing on literature in education and other fields (e.g., military), we find that although educational research has not, to date, investigated how to measure team teaching within schools, rigorous assessments of teamwork have been developed outside of education. Specifically, measures of team planning and team knowledge may prove particularly useful and could gradually be integrated within systems of teacher evaluation in schools.