Previous research by Williams, Siegel and Mazefsky (2018) investigated the relationship between verbal abilities and problem behaviors using data from the Autism Inpatient Collection (AIC). This research found a weak and inconsistent association between verbal abilities and problem behavior severity; however, adapting/coping scores were significantly associated with the problem behaviors of self-injury, stereotypies, and irritability (including aggression and tantrums) (Williams et al., 2018). The aim of the current study was 1) to determine if these findings could be replicated with a second sample of participants, and 2) to investigate the effects of language skills and augmentative/alternative communication (AAC) use on the presence of problem behaviors in individuals with autism who have complex behavioral profiles. Data was from a new sample of 260 autistic inpatients, ages 4 to 20 year, from the six psychiatric facilities of the Autism Inpatient Collection (AIC). The receptive/expressive language and nonverbal IQ scores of participants were reliably similar to the previous sample; however, the verbal group had a lower average age than in the previous study. Analysis of covariance (ANCOVA), hierarchical linear regression, and non-parametric correlation were used to address the research questions. The findings did not directly replicate those of the Williams et al. (2018) study; instead, verbal abilities were related to the problem behaviors of self-injury and stereotypies in the participants in the current sample. Specifically, problem behaviors appear to be related to communication in those individuals who were candidates for AAC but who were not reported to have access to it. Investigation of the functions of problem behaviors and the related functional equivalency of communication skills may provide further understanding of the relationships between communication, use of AAC, and problem behaviors in individuals with ASD. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]