Changes in minimal verbal communication by children with autism spectrum disorder (ASD) were measured with the Communication Complexity Scale (CCS) and other communication assessments. The CCS measures complexity of preverbal and beginning verbal communication used to communicate behavior regulation and joint attention. The purpose was to investigate if the CCS was responsive to changes associated with a behavioral intervention aimed at improving communication skills. Changes were detected with CCS scores, rates of initiating joint attention, and the Mullen Scales of Early Learning (MSEL) Expressive Language subscale. Significant changes in CCS scores were also detected for a subgroup of participants who did not show significant changes on the MSEL Expressive Language subscale, demonstrating that CCS scores are sensitive to changes associated with a behavioral intervention.