Purpose: The intersection of treatment intensity and communication intervention is an emerging area of investigation. Milieu teaching (MT) approaches for teaching communication skills to children with autism spectrum disorder (ASD) have a substantial evidence base (see Goldstein, 2002). However, a relatively small percentage (37.8%) of MT studies have fully detailed the parameters that are required to determine treatment intensity (Parker-McGowan et al., 2014). This study compared the effect of two dosages of the modeling component of milieu teaching on acquisition and maintenance of new vocabulary for two preschoolers with ASD. Method: Low- and high-dosage conditions were compared within an adapted alternating treatments design. Participants were two preschool-age children with ASD. Results: Results suggested a functional relationship between dose of MT models and acquisition of vocabulary items. For 1 participant, a high-dose application yielded more efficient acquisition. For the second participant, a low-dose application yielded more efficient acquisition. Conclusion: The results of this study highlight the influence of individual differences in ostensibly similar persons and response to intervention. The need for better quantifying dosage parameters and examining the relationship between dosage and intervention approaches for preschool-age learners with ASD is discussed.