Despite the growing body of research on how to support older readers, few studies consider whether U.S. teachers can identify students who have difficulty reading instructional materials across content areas or whether teachers feel like they have the knowledge and resources to support those students. Such information could lay the groundwork for states and school systems to provide better supports to teachers to address students' reading difficulties. In this report, researchers explore U.S. public school teachers' perceptions of students' difficulties with reading in grades 3-8, those teachers' knowledge about how students learn to read, their experiences supporting these readers, and what they need to help students become proficient readers. The findings in this report highlight the importance of including teachers in upper elementary and middle school grades in resource development and allocation and offer guidance to policymakers designing or implementing reading instruction reforms. [The research described in this report was sponsored by the Advanced Education Research and Development Fund (AERDF).]