This research study examines the impact of teacher research on participants in a large-scale educational reform initiative in the United States, No Child Left Behind, and its strand for reading teachers, Reading First. Reading First supported professional development for teachers in order to increase student scores on standardized tests. The authors were part of the team delivering university courses to augment that training so that teachers could earn graduate credit in the authors' state. Participants in the two-year study included 250-400 Reading First K-3 reading teachers in about 60 schools. In hopes of empowering teachers in what the authors felt was an over-prescriptive reading program that imposed numerous constraints on teachers, they viewed teacher research as a way to work within and against the Reading First agenda. Investigating the impact of teacher research on participants, the authors used mixed methods and found a powerful gain in teachers' self-efficacy resulting from the inquiry projects.