Peer networks are a promising intervention for increasing social interactions between students with severe disabilities and their peers. However, this approach has not been well studied with high school students who have complex communication needs and use augmentative and alternative communication (AAC). In this study, we used a multiple probe across participants design to evaluate the effectiveness of a lunchtime peer-network intervention for three high school students with autism and/or multiple disabilities who had complex communication needs. The intervention involved recruiting peers, sharing practical background information and modeling how to communicate with the student, and then providing support as needed. A functional relation was established between the introduction of the peer-network intervention and both social interactions and social engagement. Interactions increased substantially across communication modalities. This study builds on the peer-network literature by demonstrating how this approach can be tailored for high school students with complex communication needs.