Educators and therapists implement assistive technology to maximize educational outcomes of students with disabilities. However, few measure the outcomes of interventions because of a lack of valid measurement tools. This study investigated whether an assistive technology supplement for the School Function Assessment demonstrates an important aspect of construct validity. Specifically, the study examined a type of consequential validity. Twenty-eight school-based therapists participated in the study. Two t tests compared a group using the School Function Assessment (n = 13) to a group using the assistive technology supplement to the School Function Assessment (n = 15). The first t test examined the difference in confidence therapists perceived in their ability to develop assistive technology interpretations. The second t test compared the number of assistive technology interpretations matching those of an expert panel. The first t test did not achieve significance (p = .998). The second t test achieved significance (p = .001). These results suggest, with certain limitations, that the assistive technology supplement for the School Function Assessment exhibits this important aspect of construct validity.