The purpose of this study is to obtain preliminary data on the relationship between exposure to a professional development intervention (the Mathematics Coaching Program (MCP)) and student achievement. The research setting is the set of 34 mathematically low-performing elementary and intermediate schools in rural and urban locations in Ohio participating in the MCP. The MCP trains coaches to provide on-site professional development in a content-focused coaching model in MCP schools. The model includes one-on-one intensive interactions between coach and teacher for in planning, teaching and assessing students. Teachers work with coaches through a pre-teaching conference, teaching, and post-teaching conference model. Interactions are grounded in teacher and student content with improved student achievement as the desired outcome. The research employs a quasi-experimental design with some elements of randomization.