We now know a tremendous amount about early reading development, including the various skills that learners have to master and integrate to be both effective word readers and skilled comprehenders. The body of work referred to as the "science of reading" has helped illuminate these processes, and it offers important guidance for the learning opportunities that educators should be making available to students in kindergarten through third grade. However, the numerous advances of the last 50 years in the science of reading need to be complemented with equivalent attention to the "science of teaching reading." The science of teaching reading is insufficient, and the following topics each deserve a research agenda of their own: how literacy is actually taught in the classroom, and how preservice and in-service teachers learn to teach reading and learn to create and sustain learning environments. If researchers are to effectively collaborate with practitioners to improve reading outcomes, we must ask root cause questions regarding the realities of how preservice and in-service teachers learn to teach reading, and what the barriers are to effective transfer and translation of their learning to student outcomes.