Mental health parity: what are the gaps in coverage?

BACKGROUND: Mental health benefits in private health insurance plans in the United States are typically less generous than benefits for physical health care services, driving reform efforts to achieve parity in coverage. While there is growing evidence about the effects such legislation would have on the utilization and cost of mental health services, less is known about the impact parity would have on reducing the risk of large out-of-pocket expenses that families would face in the event of mental illness. AIMS OF THE STUDY: We seek to understand the impact that mental health parity would have on the out-of-pocket burden that families would face in the event of mental illness. We focus in particular on variations in coverage across the privately insured population. METHODS: We compare out-of-pocket spending for hypothetical episodes of mental health treatment, first under current insurance coverage in the United States and then under a reform policy of full mental health parity. We exploit detailed informtion on actual health plan benefits using a nationally-representative sample of the privately insured population under age 65 from the 1987 National Medical Expenditure Survey (NMES) that has been carefully aged and reweighted to represent 1995 population and benefit characteristics. RESULTS: Our results show that existing benefits of the U.S. privately insured population under age 65 leave most people at risk of high out-of-pocket costs in the event of a serious mental illness. Moreover, the generosity of existing mental health benefits varies widely across subgroups, particularly across firm size. We find significantly lower out-of-pocket costs when simulating full parity coverage. However, our results show those with less generous mental health coverage tend to have less generous physical health coverage, as well. CONCLUSIONS: Parity would substantially increase generosity of mental health coverage for most of the privately insured population. The wide variation in the generosity of existing mental health benefits suggests that there are likely to be differential impacts from a parity mandate. Those with limited physical health coverage would still be at significant financial risk for catastrophic mental illness.