The potential expansion of insurance coverage through the Patient Protection and Affordable Care Act of 2010 can facilitate the reduction of access barriers and improved quality for behavioral health care. More than 5 million of the newly insured are expected to have mental health and substance use disorders. In addition, state and federal efforts to integrate behavioral and medical health needs through patient-centered medical home models and innovations in payment strategies provide an unprecedented opportunity to use federal financial support to improve not only access to care, but also improve quality through active care coordination, use of interdisciplinary teams, colocating services, and engaging in warm hand-offs between providers in the same setting. These potential advances are hindered in 24 different states because of Medicaid payment policy, with 7 explicitly limiting the ability to reimburse for physical health and behavioral health services on the same day for all providers. Without the ability for providers to be reimbursed for different services on the same day to improve behavioral and medical health care coordination, these states could be limited in their ability to improve care via patient-centered approaches and interdisciplinary team-based care that would involve physicians, clinical psychologists, psychiatrists, and other mental health professionals. Limits on same-day billing in Medicaid programs could impact up to 36.7 million people in 24 states, which is approximately 52.6% of all Medicaid enrollees.