The present study evaluated a systematic instructional package including the system of least prompts (SLP) to teach differentiation and selection of tangible symbols to continue activities for two children with complex support needs and deafblindness (DB). A multiple probe design across three symbols was used to evaluate the intervention package for skill acquisition in both studies. Intervention sessions were conducted in the children's typical home or school settings. In Experiment 1, the participant increased symbol use for all three symbols and met the mastery criterion for one symbol. In Experiment 2, the participant met the mastery criterion for all three symbols. The intervention package, including SLP, resulted in increased skills for both participants. There was a functional relation between the SLP intervention package and symbol use and a clear increase in communicative behaviors for both children. These experiments extend the body of research on systematic instruction, including SLP, to include individuals with DB and expands the limited research base on instructional methods in the field of DB.