A fourth-grade teacher utilized action research in order to make data-driven decisions about reading interventions with her students. The teacher decided on a broad intervention, which was differentiating reading instruction, implemented differentiated instruction, collected data and continuously adjusted interventions based on monitoring data. The action research was conducted in an upper elementary school in southern Mississippi. There were two classrooms: an inclusion classroom (Class 1) and a general education classroom (Class 2). Pre- and post-tests using STAR reading were provided and scores were examined using descriptive analysis. The reading scores for both reading groups increased using differentiated reading instruction. The largest increase was found in the inclusion classroom group (Class 1). The primary focus was on the teacher implementing what was learned in a master's teacher education program concerning action research and the importance of making data-driven decisions in the classroom. The teacher examined a concern in the classroom, researched possible solutions or interventions, implemented those, monitored them, adjusted approaches, and reinforced the process of action research within the classroom.