This meta-analysis reviews the literature on communication modes, communicative functions, and AAC type examined during interventions with school-age participants with ASD and/or ID who experience CCN. Considering potential differences related to outcomes taught could help identify the most effective means of individualizing AAC interventions. We performed a comprehensive literature search. A multi-level meta-analysis was implemented across 114 included studies with 330 participants and 767 effect size using two case-level effect size metrics, Tau and log response ratio. There were few statistically significant differences found between moderator categories (e.g., communication mode, communicative function, and AAC type implemented). This is likely due, in part, to the participant heterogeneity and an under-reporting of implementation factors. A PRISMA-compliant abstract is available at https://docs.google.com/document/d/1ZMjs3WuvIjTghkqa-JzJ3wc00bnmJkHciVL6_pY4WN8/edit. [This is the online version of an article published in "Review Journal of Autism and Developmental Disorders."]