This study explored the performance of seventh-grade students with and without disabilities, educated in inclusive mathematics classes, on a mathematics assessment aligned to state standards with graphing calculators as an accommodation. The study used random assignment of classes to condition with students nested in classes. Students did not use a graphing calculator on the preassessment but approximately half (52.5%) had access to a graphing calculator on the post-assessment. The results indicate that students with disabilities made gains from preassessment to post-assessment but students without disabilities performed statistically significantly better on the post-assessment than did students with disabilities, F(1, 35) = 4.322, p = 0.045. The results raise concern about the validity of calculators as assessment accommodations for students with disabilities. (Contains 2 notes, 3 tables and 3 figures.)