The Mental Health Parity and Addiction Equity Act evaluation study: Impact on specialty behavioral healthcare utilization and spending among enrollees with substance use disorders

MHPAEA was associated with modest increases in total, plan, and patient out-of-pocket spending and outpatient and inpatient utilization. These increases, while modest in magnitude, are larger in magnitude than increases detected among a sample of all enrollees (i.e. not only those with SUD diagnoses).