ABSTRACT
Objective
To examine the association between state increases in income or asset eligibility limits for Medicare Savings Programs (MSP), which provide assistance with Medicare cost-sharing and/or premiums, and MSP enrollment and health care use.
Study Setting and Design
We used interrupted time series analysis to evaluate changes in MSP enrollment rates before and after expansion. We estimated associations between post-expansion enrollment in MSPs with outpatient visits, prescription drug fills, emergency department (ED) visits, and hospitalizations using a matched difference-in-differences approach. Matching variables included individual and area-level sociodemographic characteristics, comorbidity scores, and MSP eligibility group.
Data Sources and Analytic Sample
We used Medicare data from four states that met the inclusion criteria of having at least 24 months of data before and after their expansion between 2006 and 2019: Connecticut (income and assets), Indiana (income), New York (assets), and Oregon (assets).
Principal Findings
Relative to predicted enrollment in the absence of MSP expansion, actual enrollment over 24 months increased by varying degrees: 65.3% in Connecticut and 34.1% in Indiana, but only 3.9% and 3.7% in New York and Oregon, respectively. In Connecticut and Indiana, the two states that raised income limits, post-expansion enrollment in MSPs was associated with increased prescription drug use overall (e.g., 380 fills per 1000 beneficiaries per month in Connecticut, 95% CI: 333, 427) and in three chronic drug classes, and decreased hospitalizations (e.g., −4 hospitalizations per 1000 beneficiaries per month in Indiana, 95% CI: −7, −2).
Conclusions
MSP eligibility expansions had positive but variable impacts on enrollment across states, with larger increases in states that expanded eligibility by raising income limits versus those that only eliminated asset tests. In the states that raised income limits, post-expansion enrollment in MSPs was associated with increased use of chronic drugs, underscoring the potential clinical value of financial assistance for low-income beneficiaries.