As states work to strengthen supports for young children's mental health, often with the goal of reducing the incidence of costly conditions at later ages, they face the question of how to finance new or expanded services. This brief examines states' use of Medicaid as a key source of funding for early childhood mental health (ECMH) services. It presents the results of a 50-state survey that gathered information from state administrators about Medicaid coverage of the following services for children from birth to age 6: (1) Child screening for social-emotional problems; (2) Maternal depression screening in pediatric; and family medicine settings; (3) Mental health services in a pediatric or family medicine setting; (4) Mental health services in child care and early education settings; (5) Mental health services in the home setting; (6) Dyadic (parent-child) treatment; (7) Parenting programs to address child mental health needs; and (8) Case management/care coordination. In addition to asking about whether states cover each type of service, the survey also collected information about policies related to coverage. The results of the survey can help stakeholders from a variety of sectors, including advocates, Medicaid administrators, and leaders in early childhood and philanthropy, examine options for improving Medicaid coverage of ECMH services and the quality of covered services.