Resurgence following expanded-operant treatments (i.e., increasing the number or variability of alternative responses to problem behavior) has been the focus of numerous studies over the last five years. Researchers have evaluated several techniques for expanding the operant such as serial-, lag-, and concurrent-training procedures. Given the increasing number of recent studies on the topic, the various forms of training used, and the variability in outcomes, it is critical to review this area of research and identify clear future directions. Our brief review identified 10 published studies and eight unpublished theses or dissertations on this topic; however, only three published studies directly evaluated expanded-operant treatments as a strategy for relapse mitigation. All three studies evaluated serial-training procedures, and results across the studies were inconsistent. We summarize the findings of each study and provide recommendations for future research.