This article undertakes a reframing of the concept of teacher knowledge. It argues that in order to help teachers create more powerful learning environments, a much more general framing is required--one that incorporates a teacher's perceptions, inclinations and orientations as well as their understandings and related proficiencies. A main point of departure is the Teaching for Robust Understanding (TRU) framework, which focuses on essential dimensions of classroom practice. Questions of teacher knowledge are reframed as: "How can we reconceptualize teacher knowledge (perhaps better, teacher proficiency) so that it encompasses the broad range of perceptions, orientations, understandings and proficiencies that support teachers in crafting learning environments from which students emerge as knowledgeable, flexible, and resourceful thinkers and problem solvers? How can it be organized so that it can be worked on productively? This paper explores these issues. It employs the TRU framework as the initial mechanism for reframing, while drawing on Schoenfeld's ("How we think." Routledge, New York, 2010) work on teachers' decision making and Schoenfeld and Kilpatrick's ("International handbook of mathematics teacher education," volume 2: tools and processes in mathematics teacher education. Sense Publishers, Rotterdam, pp 321-354, 2008) work on teacher proficiency to suggest what should be included in an expanded framing of teacher knowledge.