Given the emphasis on promoting self-determination in the field of special education and the corresponding use of scales to measure self-determination in research and practice, it is important to examine whether widely used self-determination assessments measure the same constructs among and between students from different disability categories. This study examined the equivalence of measurement and structural parameters of "The Arc's Self-Determination Scale" (SDS) across groups of students with emotional and behavioral disorders (EBD) or learning disabilities (LD), using a two-group confirmatory factor analysis (CFA). The results indicated that four essential elements of self-determined behavior that form the structure of the SDS (i.e., autonomy, self-regulation, psychological empowerment, and self-realization) are invariant across the two groups. In addition, students with EBD indicated lower levels of autonomy compared with those with LD. Implications and future directions for research and practice are discussed.