The purpose of this study was to determine if there was a functional relation between a peer-delivered modified system of least prompts procedure (SLP) and an increase in level and trend of performance on finding the area of polygons or finding the volume of cylinders, spheres, and cones, and could the peer tutor reliably implement the modified SLP procedure with middle school students with mild to severe disabilities. A multiple probe days across participants design was used. Results from this study show that there was a functional relation across students in which students were able to make progress on academic math skills when taught by a peer tutor using the modified SLP procedure. The peer tutor was able to reliably implement the procedure to multiple students. Limitations and implications for practice are discussed.