Basic research has shown that behavioral persistence is often positively related to rate of reinforcement. This relation, expressed in the metaphor of behavioral momentum, has potentially important implications for clinical application. The current study examined one prediction of the momentum metaphor for automatically reinforced behavior. Participants were 3 children who had been diagnosed with an autism spectrum disorder and who engaged in stereotypic behavior maintained by automatic reinforcement. Results suggested that stereotypic behavior was more resistant to disruption following periods of access to preferred stimuli delivered on a variable-time schedule than following periods without access to preferred stimuli. The implications of these findings for the treatment of automatically reinforced behavior are discussed.