The Institute for Multi-Sensory Education's (IMSE) mission of "empowering districts, schools, teachers, and parents to be agents of change toward equitable literacy instruction for all learners that is driven by research" is reflected in the organization's structured literacy approach to the Orton-Gillingham (OG) curriculum and their related professional development opportunities for school districts and teachers. To examine the effectiveness of the IMSE OG program, with the primary consideration of submitting findings for ESSA's Evidence Standards, a quasi-experimental research design was utilized to compare treatment and control group students in first, second, and third grades on oral reading fluency. Two comparable public-school districts in Michigan were chosen for the study, which included five elementary schools (three from the control district and two from the treatment district). At each grade level, an analysis of covariance was conducted to evaluate the impact of IMSE OG teacher professional development training on student achievement. When controlling for fall reading fluency scores, students in all three grade levels who were taught by IMSE OG-trained teachers scored significantly higher on spring oral reading fluency compared to students who received the traditional curriculum.