How well does Medicaid work in improving access to care?

Objective. To provide an assessment of how well the Medicaid program is working at improving access to and use of health care for low-income mothers. Data Source/Study Setting. The 1997 and 1999 National Survey of America's Families, with state and county information drawn from the Area Resource File and other sources. Study Design. Estimate the effects of Medicaid on access and use relative to private coverage and being uninsured, using instrumental variables methods to control for selection into insurance status. Data Collection/Extraction Method. This study combines data from 1997 and 1999 for mothers in families with incomes below 200 percent of the federal poverty level. Principal Findings. We find that Medicaid beneficiaries' access and use are significantly better than those obtained by the uninsured. Analysis that controls for insurance selection shows that the benefits of having Medicaid coverage versus being uninsured are substantially larger than what is estimated when selection is not accounted for. Our results also indicate that Medicaid beneficiaries' access and use are comparable to that of the low-income privately insured. Once insurance selection is controlled for, access and use under Medicaid is not significantly different from access and use under private insurance. Without controls for insurance selection, access and use for Medicaid beneficiaries is found to be significantly worse than for the low-income privately insured. Conclusions. Our results show that the Medicaid program improved access to care relative to uninsurance for low-income mothers, achieving access and use levels comparable to those of the privately insured. Our results also indicate that prior research, which generally has not controlled for selection into insurance coverage, has likely understated the gains of Medicaid relative to uninsurance and overstated the gains of private coverage relative to Medicaid.