Teachers’ professional development (PD) is crucial to improving student outcomes. Because PD involves a multidimensional structure and changes across a teacher’s professional life, defining PD is complicated, and existing studies fail to meaningfully define it. To offer a working framework for optimal PD, we reviewed existing articles on the subject in four key journals in teacher education. We found that effective PD is attentive to assessment, research scale, duration, comprehensiveness, dissemination, context, support and control, and collaboration. We situate this conceptual framework as a new take on pre-existing definitions of PD that advises how to more effectively apply PD. •Reviewed literature on teacher’s PD to uncover best practices.•Found that teachers’ PD extends from teacher’s college to retirement.•PD is affected by teachers’ traits, materials, and pedagogies.•Effective PD is attentive to reforms, context, curriculum, and collaboration.•The components of the PD process are interrelated and interdependent.