Extended diaper wearing may limit access to inclusive opportunities including general education settings, summer camps, community-based programming, and job opportunities. Toilet training may be delayed due to more pressing concerns, such as challenging behavior. Individualized education plans should include toilet training children with intellectual and developmental disabilities (IDD) experiencing urinary accidents due to the consistency and availability of resources associated with school settings. Researchers have demonstrated that toilet training in the school setting can lead to continence for children with IDD with minimal long-term disruptions to the school day. The purpose of this study was to evaluate the effects of changing the garment type prior to implementing a classroom-based toilet training package for preschool-aged children with IDD. Researchers evaluated the effects of the garment type and toilet training package on on-toilet voids and initiated voids with a concurrent multiple probe across participants research design. All three participants reached continence and two participants began initiating trips to the restroom.