The purpose of this study was to present a policy analysis of the Mental Health Parity and Addiction Equity (MHP AE) Act of 2008. Mental illness and substance abuse disorders are prevalent social problems in the United States. This analysis examined the history of mental illness in regards to the attitudes and treatment in America, the evolution of health insurance and historical policies for parity of mental health and substance abuse treatment. Furthermore, the analysis of the policy is conducted to further understand the objectives, effects and implications of this parity law. This policy analysis used a qualitative design, collecting data from primary and secondary sources that address this policy. A modified version of David Gil's (1992) policy analysis framework was utilized to analyze the policy. The major finding of this analysis was the MHP AE Act of 2008 had a limited impact in providing mental health and substance abuse parity in specific healthcare insurance policies.