Medicare eligibility and healthcare access, affordability, and financial strain for low- and higher-income adults in the United States: A regression discontinuity analysis

Abstract

Background US policymakers are debating whether to expand the Medicare program by lowering the age of eligibility. The goal of this study was to determine the association of Medicare eligibility and enrollment with healthcare access, affordability, and financial strain from medical bills in a contemporary population of low- and higher-income adults in the US. Methods and findings We used cross-sectional data from the National Health Interview Survey (2019) to examine the association of Medicare eligibility and enrollment with outcomes by income status using a local randomization-based regression discontinuity approach. After weighting to account for survey sampling, the low-income group consisted of 1,660,188 adults age 64 years and 1,488,875 adults age 66 years, with similar baseline characteristics, including distribution of sex (59.2% versus 59.7% female) and education (10.8% versus 12.5% with bachelor’s degree or higher). The higher-income group consisted of 2,110,995 adults age 64 years and 2,167,676 adults age 66 years, with similar distribution of baseline characteristics, including sex (40.0% versus 49.4% female) and education (41.0% versus 41.6%). The share of adults age 64 versus 66 years enrolled in Medicare differed within low-income (27.6% versus 87.8%, p Conclusions Medicare eligibility and enrollment at age 65 years were associated with improvements in healthcare access, affordability, and financial strain in low-income adults and, to a lesser extent, in higher-income adults. Our findings provide evidence that lowering the age of eligibility for Medicare may improve health inequities in the US. Rahul Aggarwal and colleagues explore the association of Medicare eligibility and enrollment with health care access, affordability, and financial strain from medical bills in low- and higher-income adults in the US. Author summary Why was this study done? In the United States, low-income adults are more likely to lack health insurance coverage, face barriers accessing healthcare, and disproportionately experience financial strain due to healthcare expenditures compared with higher-income adults. Policymakers are increasingly debating whether to expand the Medicare program by lowering the age of eligibility. We determine if Medicare eligibility and enrollment at age 65 years is associated with changes in healthcare access, affordability, and financial strain for low-income and higher-income adults. What did the researchers do and find? In this cross-sectional study, Medicare eligibility and enrollment were associated with decreases in the percentage of low-income adults who delayed or avoided medical care due to costs, as well as in the percentage whom were worried about or had problems paying medical bills. These findings were more modest and less consistent in higher-income adults. Medicare was not associated with changes in the percentage of low-income or higher-income adults who experienced cost-related barriers to medication use. What do these findings mean? As the debate on lowering the age of Medicare eligibility continues, policymakers should consider the potential implications of doing so on healthcare access and affordability for low-income adults and, more broadly, health equity in the US.