The current study examined vocalizations that occurred during training of the Picture Exchange Communication System for three U.S. preschool-age participants with autism spectrum disorder. In Phase IV, the protocol incorporates a delay to reinforcement in an effort to encourage vocalizations; however, the manual does not suggest additional strategies to try when vocalizations do not occur during the delay to reinforcement. Researchers evaluated a vocal model prompt following the delay to reinforcement and continued to measure vocalizations when the delay to reinforcement alone did not increase vocalizations. Two of the three participants increased independent vocalizations after the addition of the vocal model. Implications for practitioners and future research are discussed.