Causal evaluations in teacher education are rare. Underlying reasons include a lack of clearly defined treatments, a lack of research designs that can work in the context of teacher education programs, and a lack of resources for enacting these designs. This article provides a framework for how to fill these gaps. We first propose an approach to conceptualizing treatments and then describe two research designs suited to the needs of the field. Finally, we discuss resources key to advancing causal research in teacher education at scale.