In the context of problem behavior, treatment integrity refers to the extent to which a behavioral intervention is implemented as intended. Treatment-integrity errors may lead to relapse of problem behavior. For example, omitting reinforcers can lead to increases in problem behavior called resurgence. Researchers have previously described the clinical implications of omitted reinforcers and resurgence, including a variety of methods for mitigating resurgence. However, omission errors are not the only type of treatment-integrity errors. Delivery of unplanned reinforcers (a "commission error") can lead to recurrence of problem behavior through "reinstatement." Unlike omitted reinforcers and resurgence, the research base on commission errors and reinstatement of problem behavior is limited. In this article, we describe a few considerations relevant to reinstatement as it applies to commission errors and clinical practice.