The Impact of Medicaid Enrollment on Veterans Health Administration Enrollees' Behavioral Health Services Use.

Objective: To examine Veterans Health Administration (VA) enrollees' use of VA services for treatment of behavioral health conditions (BHCs) after gaining Medicaid, and if VA reliance varies by complexity of BHCs.

Data Sources/study Setting: VA and Medicaid Analytic eXtract utilization data from 31 states, 2006-2010.

Study Design: A retrospective, longitudinal study of Veterans enrolled in VA care in the year before and year after enrollment in Medicaid among 7,249 nonelderly Veterans with serious mental illness (SMI), substance use disorder (SUD), posttraumatic stress disorder (PTSD), depression, or other BHCs.

Data Collection/extraction Methods: Utilization and VA reliance (proportion of care received at VA) for BH outpatient and inpatient services in unadjusted and adjusted analyses.

Principal Findings: In adjusted analyses, we found that overall Veterans did not significantly change their use of VA outpatient BH services after Medicaid enrollment. In beta-binomial models predicting VA BH outpatient reliance, veterans with SMI (IRR = 1.38, p < .05), PTSD (IRR = 1.62, p < .01), and depression (IRR = 1.36, p < .05) had higher reliance than veterans with other BHCs after Medicaid enrollment.

Conclusions: While veterans did not change the amount of VA outpatient BH services they used after enrolling in Medicaid, the proportion of care they received through VA or Medicaid varied by BHC.