A controversial innovation within the rapidly expanding field of teacher education is the relocation of teacher preparation to new graduate schools of education (nGSEs), which are not university based but are state authorized and approved as institutions of higher education to prepare teachers, endorse them for initial teacher certification, and grant master's degrees. Despite media attention and both public and private funding, however, there is little empirical research about the phenomenon of teacher preparation at nGSEs based on access to actual programs, participants, materials, and institutional records. This article is the first in a planned series that draws on a Spencer Foundation-funded study of teacher preparation at nGSEs to introduce the phenomenon. It has three purposes: to situate the emergence of teacher preparation at nGSEs within larger professional, policy, and political contexts; to define and clarify the characteristics of teacher preparation at nGSEs and identify its institutional domain; and to present a field- and theory-informed analytic framework for studying teacher preparation at nGSEs.