The acquisition of reading skills is vital for all individuals given the ubiquitous influence of reading on academic outcomes and quality of life. Individuals with complex communication needs, requiring the supports of augmentative and alternative communication (AAC), are often excluded from learning phonological approaches to literacy. Most literacy approaches require verbal production of speech sounds--which is particularly difficult for individuals with complex communication needs. However, despite challenges with spoken production of sounds, research has reported positive outcomes in participation in phonological interventions when they are adapted to meet the needs of individuals who use AAC. The purpose of the current study was to conduct a systematic review to evaluate the effectiveness of foundational reading interventions (specifically phonological awareness skills, letter-sound correspondences, and decoding interventions) designed to meet the needs of individuals who use AAC. Results indicate that large and very large effects are observed with adapted phonological interventions for individuals who use AAC. These results are consistent across ages, diagnoses, most interventionists, and phonological skills (e.g., decoding, letter-sounds, sound blending). Future research shifting away from very controlled settings with the researcher (to small and large group instruction, instruction by common service providers like teachers, or other types of instruction) may be particularly valuable to support access to, and implementation of, foundational reading interventions for individuals with complex communication needs who require AAC.