Token systems often involve a predetermined number of tokens required prior to exchange for a terminal reinforcer. The effectiveness of token systems implemented in this manner has been well documented within the literature; however, some have discussed the possibility of a fixed earning requirement creating a context in which the learner no longer emits the desired behavior once the terminal number is achieved. A possible alternative to a fixed earning requirement is selecting the earning requirement based upon learner responding and leaving the requirement unknown to the learner until the moment of exchange. The purpose of this study was to evaluate the effectiveness of a token system with a flexible earning requirement to increase the frequency of comments during snack for 3 children diagnosed with autism spectrum disorder. The results of a nonconcurrent multiple-baseline design demonstrated the flexible token system was effective at increasing the rate of comments in addition to the cumulative number of novel comments. Keywords token system. flexible. shaping. commenting. autism A token economy is a contingency system in which tokens are earned for engaging in desired behavior that can be exchanged for presumably reinforcing items or activities. Token economies are commonly used in behavioral intervention to improve desired behavior and decrease the probability of undesired behavior (Hackenberg, 2018; Kazdin, 1977; Matson & Boisjoli, 2009). Ayllon and Azrin (1965) first described the use of a token economy with residents in a state hospital; however, they had been developing and modifying the procedures since 1961 (Ayllon & Azrin, 1968). Ayllon and Azrin (1965) provided tokens to residents contingent upon the resident displaying a predetermined behavior (e.g., selfgrooming, doing laundry). The tokens earned by each resident could then be exchanged for a variety of activities (e.g., walking around the hospital grounds). The results demonstrated