The Government Accountability Office (GAO) has responded to a request by Congresswoman Diana DeGette (D-CO) to examine access to treatment for behavioral health needs. The GAO found greater availability for services in states that expanded their Medicaid program under the ACA then those states that have not expanded.

The report indicated that states with expanded Medicaid have been able to provide health insurance to additional residents without incurring additional costs. The ACA at first mandated expanded Medicaid coverage for families and individuals above the poverty level, (138 percent) an annual income up to $32,923 for a family of four, or $16,242 for an individual. The 2012 Supreme Court (NFIB V Sebelius) decision changed the mandate into a state option. States generally reported that Medicaid expansion had resulted in greater availability of behavioral health treatments although there were still challenges. The changes were even greater in states without previous coverage options for a low income individuals. In particular the GAO looked at Kentucky, Nevada and West Virginia. The report also noted that in those states that did not to expand Medicaid, their tended to be waitlists for drug treatment and mental health services. Degette had requested the study because of research that indicates that the uninsured have a higher rate of behavioral health issues with behavioral health being defined as mental health and substance use conditions. The GAO reports indicates in 2013 there were an estimated 43 million adults (or more than 18%) had a mental health condition which included 10 million adults with a serious mental illness and 20 million or 8.5% had a substance use condition.

The GAO report wrote that 48 percent of public mental health treatment funding comes from Medicaid another 40 percent is from general state funds, 3 percent is from Medicare, 2 percent local funds, 1 percent the mental health block grant with the last 5 percent from other funding sources.

Twenty-nine states and the District of Columbia have expanded health care coverage The GAO analyzed Medicaid enrollment from July 2014 until June 2015 and conducted interviews from behavioral health agencies in 10 states.