The purpose of this investigation was to determine if Native American children with moderate to severe receptive vocabulary delays would benefit from the use of the web-based program InferCabulary as an effective approach to increase receptive vocabulary. The investigation took place in the computer lab at an elementary school on a Pueblo Reservation in New Mexico. A concurrent multiple baseline across participants, single case research design was used for this investigation. It included five Native American students between 7.0 and 8.11 years of age with moderate to severe receptive vocabulary delays. Four boys and one girl participated in the investigation and were provided 12 intervention sessions. The participants were randomly assigned for a staggered start of a two-data point baseline. Vocabulary knowledge for Tier 2 words was assessed at each baseline session and at the beginning of each intervention session. In addition, accuracy percentages obtained on a vocabulary task via a web-based application were documented for each participant. The data were analyzed by examining the level, trend, and stability of data assessed within and between conditions and the slope of the pretest accuracy and percent accuracy of the intervention phase. Also, to determine the significance of the change between the pretest and intervention phases, the two standard deviation band method and percentage of non-overlapping data were analyzed. Four out of five participants demonstrated positive statistically significant changes from the pre-test at the beginning of the therapy intervention to the post-test at the completion of the therapy intervention. These findings suggest that Native American children with moderate to severe vocabulary delays may demonstrate receptive vocabulary growth using InferCabulary. This research also indicates the need for continued research for this population.