This qualitative study examined how secondary teachers were assigned to teach courses intended to expand English learners' (ELs') access to academic subjects. Theoretically, this research extends the "contexts of reception" framework from immigration studies into the educational realm by investigating how teachers--as one important contextual variable--entered into settings designed for immigrant-origin ELs. Analysis examined institutional processes, norms, and policies as well as participants' practices. Findings suggest that novice teachers were most likely to be placed into separate EL content-area classrooms, unless more senior teachers requested these assignments or administrators intervened. Ultimately, this article uses teacher assignment processes to illustrate how contexts for immigrant-origin youth are constructed and contested and how ELs' opportunities to learn were jeopardized in local settings.