Loss of Subsidized Drug Coverage and Mortality among Medicare Beneficiaries

Abstract

Background: A total of 14 million Medicare beneficiaries receive the Low-Income Subsidy (LIS), which reduces cost sharing in Medicare Part D. Losing the LIS may impede medication access and affect mortality.

Methods: Using 2015-2023 Medicare data, we identified dual-eligible Medicare-Medicaid beneficiaries, who automatically receive the LIS, and calculated annual rates of Medicaid and LIS loss. To examine the relationship between LIS loss and mortality, we leveraged a natural experiment arising from the relationship between the timing of Medicaid disenrollment and subsequent LIS loss. We compared beneficiaries disenrolling from Medicaid in January through June, who kept the LIS through December (6 to 11 additional months), with those disenrolling in July through December, who kept the LIS through the following December (12 to 17 additional months). Among persons disenrolling from Medicaid during 2015-2017, we examined cumulative mortality 7 to 17 months after disenrollment, when those with earlier disenrollment were more likely to lose the LIS.

Results: The sample included 969,606 persons with early (January though June) Medicaid disenrollment and 920,158 with late (July though December) Medicaid disenrollment. Those with early Medicaid disenrollment averaged 13.6 cumulative months of the LIS in the 17 months after disenrollment, as compared with 15.3 months for those with late disenrollment. At 17 months after Medicaid disenrollment, cumulative mortality was higher among persons with early disenrollment (78.3 per 1000) than among those with late disenrollment (75.3 per 1000), a difference of 3.0 deaths per 1000 (95% confidence interval [CI], 2.1 to 3.9). Mortality differences between persons with early disenrollment and those with late disenrollment were amplified among those in the highest quintile of baseline Part D spending (5.6 deaths per 1000; 95% CI, 3.3 to 7.9) and users of medications for cardiovascular disease, chronic lung disease, or human immunodeficiency virus infection.

Conclusions: Loss of drug subsidies after Medicaid disenrollment was associated with higher mortality among low-income Medicare beneficiaries. (Funded by the National Institute on Aging and others.).