Middle and high school teachers across academic disciplines face increased pressure to address the Common Core State Standards (CCSS) for English language arts and for literacy in history/social studies, science, and technical subjects. This means that the responsibility of preparing students to read, write, talk, and think critically about complex texts and across such texts is no longer just the English teacher's job. Most secondary teachers already feel rushed to cover the subject matter content that will be assessed on current high-stakes tests. Many also feel that their primary goal of helping students build deep disciplinary knowledge has been sacrificed to the demands of superficial content coverage. The suggestion that they teach reading and writing as well as disciplinary content seems an impossible addition to an already-packed syllabus. Because most secondary teachers have not been successfully prepared to teach reading in their discipline, many no longer see reading as a viable way for most students to learn. Solutions to the challenge of bringing reading into content-area classrooms are more complex than teaching a set of isolated generic reading comprehension strategies such as summarizing and questioning. Indeed, years of research on teaching teachers to use such reading comprehension strategies point to meager returns. Since 1995, the authors have developed a set of inquiry-based professional development tools that leverage teachers' expertise as readers, writers, and thinkers in their own disciplines. Through these inquiries, teachers learn to apprentice their students to the practice of reading and comprehending complex subject matter texts. This article discusses the Reading Apprenticeship instructional framework and accompanying professional development which help teachers support secondary students to develop positive literacy identities and engage productively with challenging academic texts. Teachers working with the Reading Apprenticeship model often see a dramatic, positive transformation not only in students' literacy, but also in their engagement and achievement in academic disciplines.