This study examined the academic engaged time of six students with low incidence disabilities who were enrolled in general elementary classrooms. These students participated in regular classes for reading or math, and at least one other subject area. The academic engaged time of these students was compared to that of six students without disabilities enrolled in the same classes. The academic engaged time of students without disabilities in inclusive classrooms was further compared with six same-grade peers without disabilities who attended the same school but whose classes did not include children with low incidence disabilities. Three dependent measures were used in the study, including the frequency of observation intervals that students were engaged in academic responding, task management, and competing behaviors as defined within The Code for Instructional Structure and Academic Response-Mainstream Version (MS-CISSAR). Comparisons among groups were completed through the use of nonparametric statistical analyses. The primary results of the study were that: (1) there were no significant differences in the academic responding and task management behaviors of students (with and without disabilities) who were enrolled in general education classes; (2) significant differences were found between these two groups on the frequency of competing behaviors; (3) there were no significant differences between students without disabilities on the measures of academic responding and task management behaviors; and (4) significant differences were found between students without disabilities on the frequency of competing behaviors. Five tables present data and statistical analysis. Contains 16 references. (Author)