A single-case withdrawal design replicated across three families was used to evaluate the impact of the manualized Prevent-Teach-Reinforce for Families (PTR-F) process for addressing challenging behavior. Results across three families showed that (a) families reached high-fidelity implementation of the behavior support plans (BSPs) developed using the PTR-F process, (b) functional relations existed between parent implementation of the BSP strategies and child behavior, and (c) families perceived the PTR-F process and the BSPs as socially valid. Our results replicated findings from prior research on the general efficacy of the PTR process when extended to its use by adult family members in home settings. Implications for practice and future research are discussed.