The Affordable Care Act (ACA) extended dependent care coverage to all individuals under age 26. The coverage expansion in 2010 likely caused an increase in private insurance coverage and mental health treatment use for young adults. For mental health and substance use treatment, changes in who pays for care can be evaluated using the Medical Expenditure Panel Survey (MEPS). Annual data from 2004 to 2012 were used to determine the average treatment payments by payer type before and after the dependent care expansion for all individuals aged 19-26 who reported treatment for mental health or substance use issues. Costs are presented in this spotlight.