Medicaid Expansion Under the Affordable Care Act: Potential Changes in Receipt of Mental Health Treatment Among Low-Income Nonelderly Adults With Serious Mental Illness.

OBJECTIVES: We designed this study to examine differences in receipt of mental health treatment between low-income uninsured nonelderly adults with serious mental illness (SMI) who were eligible for Medicaid under the Affordable Care Act (ACA) and their existing Medicaid counterparts. Assessing these differences might estimate the impact of the Medicaid expansion efforts under the ACA on receipt of mental health treatment among uninsured nonelderly adults with SMI. METHODS: We examined data from 2000 persons aged 18 to 64 years who participated in the 2008 to 2013 National Survey on Drug Use and Health, had income below 138% of the federal poverty level, met SMI criteria, and either were uninsured (n = 1000) or had Medicaid-only coverage (n = 1000). We defined SMI according to the Alcohol, Drug Abuse, and Mental Health Administration Reorganization Act. We used descriptive analyses and logistic regression modeling. RESULTS: In the 28 states currently expanding Medicaid, the model-adjusted prevalence (MAP) of receiving mental health treatment among Medicaid-only enrollees with SMI (MAP = 71.3%; 95% confidence interval [CI] = 65.74%, 76.29%) was 30.1% greater than their uninsured counterparts (MAP = 54.8%; 95% CI = 48.16%, 61.33%). In the United States, the MAP of receiving mental health treatment among Medicaid-only enrollees with SMI (MAP = 70.4%; 95% CI = 65.67%, 74.70%) was 35.9% higher than their uninsured counterparts (MAP = 51.8%; 95% CI = 46.98%, 56.65%). CONCLUSIONS: Estimated increases in receipt of mental health treatment because of enrolling in Medicaid among low-income uninsured adults with SMI might help inform planning and implementation efforts for the Medicaid expansion under the ACA.