The preparation of bilingual teachers for bilingual education programs, from transitional and late-exit to more current dual-language orientations, has remained fairly stable over the past forty years: New bilingual teachers are taught to strictly separate named languages for literacy and content area instruction, and to discourage their students from mixing named languages in any classroom discourse (Creese & Blackledge, 2010; Faltis & Valdés, 2016). There are multiple reasons for this long standing tradition in bilingual education, and throughout this chapter, the intention to show how the tradition likely came to be socially constructed. In the later sections of the paper, a grand counter-narrative to the separate language approach to bilingual education and dual-language education is presented through the examination of two major approaches to bilingual teacher education that reflect the current multilingual turn (May, 2014) in attempting to understand codeswitching and translanguaging for instruction and learning. The grand counter narrative offered in this chapter encourages bilingual teachers and their students to draw from and use “their linguistic repertoires across various modalities (reading, writing, speaking, and listening), … in order to meaningful learn” (García & Woodley, 2015, p. 141) and to understand pedagogical codeswitching practices to engage bilingual learners in bilingual and dual-language programs. This chapter limits the discussion to US public school contexts, owing to my lack of experience preparing bilingual public school teachers outside of the US There has been, nonetheless, some important work on codeswitching in school settings done in African, Asian, and European countries beyond the scope of this chapter (see, for example, Alvarez-Cáccamo, 1990; Alvarez-Cáccamo, 1998; Auer, 1998; Lin, 2013; Setati, 1998; Li, 2005).