Despite estimates of rising prevalence of children with autism spectrum disorder (ASD) in the US, there is little research on the availability of behavioral health care services for this vulnerable population. To fill the gap, we surveyed 8,184 mental health treatment facilities in the contiguous US. As of August 2019, 43.0 percent of facilities reported providing behavioral health care for children with ASD, and 36.6 percent were accepting such children as new patients. Only 12.7 percent reported having a clinician with specialized training, and 4.3 percent reported having a specialized treatment program. Multivariable regression results indicated that there was poorer access to specialized ASD care in rural and lower-income communities. New policies are needed to increase the availability of behavioral health care for children with ASD.