The impact of Medicaid expansion on spending and utilization by older low‐income Medicare beneficiaries

Abstract

ObjectiveTo examine indirect spillover effects of Affordable Care Act (ACA) Medicaid expansions to working‐age adults on health care coverage, spending, and utilization by older low‐income Medicare beneficiaries.Data Sources2010–2018 Health and Retirement Study survey data linked to annual Medicare beneficiary summary files.Study DesignWe estimated individual‐level difference‐in‐differences models of total spending for inpatient, institutional outpatient, physician/professional provider services; inpatient stays, outpatient visits, physician visits; and Medicaid and Part A and B Medicare coverage. We compared changes in outcomes before and after Medicaid expansion in expansion versus nonexpansion states.Data Collection/Extraction MethodsThe sample included low‐income respondents aged 69 and older with linked Medicare data, enrolled in full‐year traditional Medicare, and residing in the community.Principal FindingsACA Medicaid expansion was associated with a 9.8 percentage point increase in Medicaid coverage (95% CI: 0.020–0.176), a 4.4 percentage point increase in having any institutional outpatient spending (95% CI: 0.005–0.083), and a positive but statistically insignificant 2.4 percentage point change in Part B enrollment (95% CI: −0.003 to 0.050, p = 0.079).ConclusionsACA Medicaid expansion was associated with more institutional outpatient spending among older low‐income Medicare beneficiaries. Increased care costs should be weighed against potential benefits from increased realized access to care.