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Member Research & Reports

Member Research & Reports

UMass: Research Shows Federal Parity Law Improved Medicaid Acceptance at Substance Use Disorder Treatment Centers

A 2008 federal parity law succeeded in expanding Medicaid acceptance by treatment facilities for substance use disorders (SUDs), according to a study led by University of Massachusetts Amherst School of Public Health and Health Sciences faculty members Dr. Kimberley Geissler and Dr. Elizabeth Evans.

Congress passed the Paul Wellstone and Pete Domenici Mental Health Parity and Addiction Equity Act in 2008 to require equal coverage of treatment for mental illness and addiction. The law went into effect in 2010, but little has been known about its impact, notes Dr. Geissler, the study’s lead author.

“The goal of parity was to make insurance coverage of mental health treatment and substance use treatment on par with insurance coverage for physical health,” she says.

The researchers analyzed 2002-2013 data from the National Survey of Substance Abuse Treatment Services for all SUD treatment facilities, combined with state-level characteristics. They limited their analysis to the period before 2014, when the Affordable Care Act (ACA) took effect, because the ACA also included provisions to expand Medicaid coverage of SUD.

The researchers found that the Medicaid acceptance rate increased by more than 10 percentage points over the study period, and the adjusted increase due to parity was about 5 percentage points.

“We were able to isolate the impacts, and we found a measurable positive effect of parity,” Dr. Geissler says.

Following the parity law, ACA made SUD treatment an “essential health benefit,” requiring coverage under certain insurance plans. The parity law was a crucial piece of that evolving process.

“Our findings underscore how parity laws are critical policy tools for…vulnerable and underserved populations with SUD to access needed health care,” Drs. Geissler and Evans conclude in their paper.

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