Students are expected to comprehend and produce increasingly complex texts in upper elementary school, and academic language and literacy skills are considered critical to meeting these expectations. Notions of academic language are also controversial and require careful deliberation when applied to traditionally minoritized populations, including bilingual learners who negotiate more than one language in their daily lives and have varied linguistic repertoires. In the present study, the authors report on a quasi-experimental field trial of a theoretically grounded and language-based reading intervention framed around language components (semantics, syntax, and morphology), language functions, discussion, and reading comprehension. A sample of 239 Portuguese--English and Spanish--English bilingual students in grades 4 and 5 worked in small instructional groups to explore language, apply reading strategies, and discuss and write about big ideas in text. Half of the students were assigned to the intervention group (n = 119) and the other half (n = 120) to a business-as-usual control group. Classroom teachers (n = 12) and specialists (n = 10) implemented the intervention with small groups of four to six students. Results showed practically meaningful effects of the intervention on standardized measures of both academic language (Hedges's g = 0.248) and reading comprehension (Hedges's g = 0.166), with implications for theory, research, and classroom practice.