Autism Spectrum Disorder (ASD) is associated with significant healthcare expenditures and a greater utilization of psychiatric health services. High utilization may not be evenly distributed across individuals with ASD. The objective of this study was to identify individual and family characteristics that increase the risk of psychiatric hospitalization. Naturalistic study of two age- and gender-matched ASD cohorts, inpatients enrolled in the Autism Inpatient Collection (AIC) and outpatients enrolled in the Rhode Island Consortium of Autism Research and Treatment (RI-CART), revealed a number of factors associated with hospitalization. Multiple logistic regression analyses revealed that adaptive functioning, ASD symptom severity, primary caregiver’s marital status, the presence of mood disorders, and the presence of sleep problems independently increased the risk of psychiatric hospitalization.