The Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act (MHPAEA) of 2008 is Federal legislation that requires that group health plans and health insurance coverage offered in connection with group health plans offer mental health and substance use disorder (MH/SUD) benefits in a manner comparable to medical and surgical (M/S) benefits. In California, the Department of Managed Health Care (DMHC) is responsible for overseeing the implementation of MHPAEA by managed health care plans.