--- - |2 Functional communication training is a well‐established treatment for socially reinforced destructive behavior that typically includes differential reinforcement of the functional communication response (FCR) in combination with extinction of destructive behavior. However, when the schedule of reinforcement for the FCR is thinned, destructive behavior may resurge (e.g., Greer, Fisher, Saini, Owen, & Jones, 2016). Currently, data are unavailable on the prevalence and characteristics of resurgence during reinforcement schedule thinning. In this study, we evaluated the prevalence of resurgence during reinforcement schedule thinning on a per‐case and per‐schedule‐step basis and also evaluated the magnitude of resurgence in relation to the functions of destructive behavior. We observed resurgence in 19 of the 25 (76%) applications of reinforcement schedule thinning. In some cases, the magnitude of resurgence exceeded the mean levels of destructive behavior observed in baseline. We discuss these results relative to prior translational and applied research on resurgence. - Journal of Applied Behavior Analysis, Volume 51, Issue 3, Page 620-633, Summer 2018.