Adverse childhood experiences (ACEs) are risk factors for mental and physical illness and more likely to occur for children with autism spectrum disorder (ASD). The present study aimed to clarify the contribution of poverty, intellectual disability and mental health conditions to this disparity. Data on child and family characteristics, mental health conditions and ACEs were analyzed in 67,067 youth from the 2011–2012 National Survey of Children’s Health. In an income-stratified sample, the association of ASD and ACEs was greater for lower income children and significantly diminished after controlling for child mental health conditions, but not intellectual disability. Findings suggest that the association of ACEs and ASD is moderated by family income and contingent on co-occurring mental health conditions.