Young students with ASD have instructional needs in social, communication, and learning skills that should be reflected in their Individualized Education Program (IEP). Research suggests that many of these goal areas present a challenge for special educators because of problems with measurability. The current study utilized an idiographic approach called Goal attainment scaling (GAS) for measuring IEP progress of individualized skills. Cross-sectional analysis of the associations between GAS ratings from an independent observer were correlated against teacher and parent ratings of IEP progress at the end of the school year and with standardized measures of the Behavior Assessment System for Children and Vineland Adaptive Behavior Scales (VABS). GAS scores were associated with parent and teacher ratings, including the VABS.