Changes in Medicaid Acceptance by Substance Abuse Treatment Facilities After Implementation of Federal Parity

Adequate access for mental illness and substance use disorder (SUD) treatment, particularly for Medicaid enrollees, is challenging. Policy efforts, including the Mental Health Parity and Addiction Equity Act (MHPAEA), have targeted expanded access to care. With MHPAEA, more Medicaid plans were required to increase their coverage of SUD treatment, which may impact provider acceptance of Medicaid.

To identify changes in Medicaid acceptance by SUD treatment facilities after the implementation of MHPAEA (parity).

Observational study using an interrupted time series design.

2002-2013 data from the National Survey of Substance Abuse Treatment Services (N-SSATS) for all SUD treatment facilities was combined with state-level characteristics.

Primary outcome is whether a SUD treatment facility reported accepting Medicaid insurance.

Implementation of MHPAEA was associated with a 4.6 percentage point increase in the probability of an SUD treatment facility accepting Medicaid (P<0.001), independent of facility and state characteristics, time trends, and key characteristics of state Medicaid programs.

After parity, more SUD treatment facilities accepted Medicaid payments, which may ultimately increase access to care for individuals with SUD. The findings underscore how parity laws are critical policy tools for creating contexts that enable historically vulnerable and underserved populations with SUD to access needed health care.