Purpose: The purpose of this study was to further evaluate an eight-step partner instructional model developed by Kent-Walsh and McNaughton that has been demonstrated to improve implementation quality and fidelity among adults in clinical and educational settings who support the use of augmentative and alternative communication (AAC) for individuals with complex communication needs. Method: This study examined the effectiveness of the eight-step model in a K-12 special education setting. Participants included 26 staff and 19 students. Effects on both communication partner modeling and student AAC system use were assessed. The study expanded upon prior research by employing a group design, including largely adolescent participants, and utilizing multiple AAC hardware and software types. Results: Staff receiving training and coaching via the full eight-step model demonstrated gains in the percentage of utterances modeled, and their student partners increased mean length of utterance. The study failed to find statistically significant differences between the experimental group and a comparison group receiving only Stages 1-5 of the model. Conclusion: Findings provide additional evidence for the viability of the eight-step instructional model as a methodology to promote the communication skills of students who utilize AAC, and also point to the advanced practice and feedback element of the model as a potential mediator of intervention outcomes.