The General Social Outcome Measure (GSOM) is a performance-based measurement tool designed to assess the change in social skills performance during and after intervention for students with social skills deficits. In the current study, the psychometric properties of the GSOM, including the total score and social communication domains, were examined using a sample of U.S. in adolescents with social skill deficits. Internal consistency alphas were conducted, which showed promising results. Correlational analyses were conducted using the GSOM and the Children's Communication Checklist-2 (CCC-2), School Social Behavior Scales (SSBS), and the Autism Diagnostic Observation Schedule--Second Edition (ADOS-2). A small but significant correlation was documented between the GSOM and the ADOS-2, with higher GSOM total scores (higher social skills) associated with lower ADOS-2 scores. Additional analyses revealed that individuals with different levels of symptomology according to the ADOS-2 (low, moderate, or high) differed significantly in the GSOM total score. The implications of these findings are discussed with respect to the utility of the GSOM as a progress-monitoring tool for targeted populations with social skill impairments.