Mothers of autistic children often report poor mental health outcomes. One established risk factor for these outcomes is the child having a medical home. This study examined possible mediating variables (coping, social support) in this relationship in 988 mothers of autistic children from the 2017/2018 National Survey of Children's Health (NSCH). The results of the multiple mediation model suggest the relationship between having a medical home and maternal mental health is largely explained by indirect associations with coping and social support. These findings suggest that clinical interventions for coping and social support provided by the medical home for mothers of autistic children may improve maternal mental health outcomes over and above implementation of a medical home.