This case study of reading activity in third-grade bilingual classrooms at a state-sanctioned "successful" school examines the influences of the California accountability framework--Proposition 227, No Child Left Behind, and the federal Reading First program--on shifting beliefs and practices around what "counts" as reading. The researcher utilized cultural-historical theoretical perspectives on the socioculturally mediated nature of teaching and learning to examine the joint construction of reading activity as well as account for the institutional constraints within which teachers and their students accomplished this work. Specifically, she employed participant observations and video recordings of Spanish and English language arts instructional periods, in-depth teacher and administrator interviews, a collection of student work samples, and a collection of relevant school and district documents to examine the mediation of reading activity across school, district, state, and federal policy contexts. To examine the dialectical relationship between policy and practice, she analyzes two bilingual classrooms in depth through heuristic tools that illuminate how particular discourse patterns and participation structures align broadly with policy-sanctioned notions of what counts as reading. Analyses of narrative texts and transcripts illustrate that this alignment had implications for English-language learners' meaning-making opportunities. This analysis contributes a theoretical conceptualization of reading activity as implicated in the dialectical relationships between policies, practices, resources, and beliefs around what counts as reading across institutional contexts and how these processes affect English-language learners' reading potential. (Contains 4 figures and 3 tables.)