The goal of this study was to build the capacity of early childhood teachers to implement evidence-based strategies. We investigated the efficacy of professional development with bug-in-ear peer coaching in improving teachers' use of communication strategies, the teachers' maintenance of strategies post intervention, and the social validity of the intervention. Four early childhood co-teacher dyads participated in the single-case design study. Data were analyzed through visual analysis and masked visual analysis. Results indicate that three of the four teacher dyads increased the frequency with which they used the strategies, with one dyad sustaining their use targeted strategies post intervention. All teachers perceived that the intervention had positive effects on their children and indicated that bug-in-ear peer coaching was an acceptable form of professional development. Nonetheless, implications for research and practice are discussed to ensure that performance-based feedback is as meaningful as possible. [At the time of submission to ERIC this article was in press with "Topics in Early Childhood Special Education."]