This presentation will discuss the likely impacts of Mental Health Parity and Addiction Equity Act on substance abuse treatment services use and costs based on an analysis of health insurance claims and health insurance booklets. The data are from approximately 100 large, self-insured employers and millions of enrollees covering the period 2001–2009. Among the findings is that overall, parity for substance abuse service is unlikely to have a significant impact on overall health care spending. Services that may be impacted by parity include use of particular medications which currently have utilization restriction, such as suboxone, and use of particular services, such as residential treatment services, which are often excluded from benefit packages. The use of and access to these service…