Functional communication training is an effective intervention for establishing an appropriate, alternative response that produces the functional reinforcer maintaining challenging behavior. Once the alternative response is established, it is differentially reinforced—typically using dense schedules—while challenging behavior is placed on extinction. After achieving clinically significant reductions in challenging behavior, reinforcement schedule thinning is conducted to promote the maintenance of the alternative response under more practical reinforcement schedules. In the current study, we compared two different methods for thinning the schedule of reinforcement for the alternative response to a terminal schedule. One method, referred to as the dense‐to‐lean (DTL) approach, involves gradually decreasing the density of alternative reinforcement over successive sessions until the terminal schedule is reached. Another method, referred to as the fixed‐lean (FL) approach, involves abruptly decreasing the density of alternative reinforcement by rapidly transitioning to the terminal schedule. Whereas the former approach has been evaluated extensively within the applied literature, the latter approach has not been the focus of much empirical work in either the clinic or the laboratory. An alternating treatment design was used to directly compare these approaches, both of which included noncontingent access to competing stimuli. Participants achieved clinically significant reductions in challenging behavior at the terminal schedule more readily with the FL than the DTL approach. The results are further discussed in terms of the efficacy and efficiency for both approaches, the potential mediating effect of competing stimuli, and implications for future research.