Abstract
INTRODUCTION: The Inflation Reduction Act (IRA) eliminated cost sharing for Medicare Part D-covered vaccines but did not address the cost burden faced by Medicare beneficiaries who did not have prescription drug coverage. This study aimed to determine the characteristics of beneficiaries without prescription drug coverage and to assess the association between the receipt of a herpes zoster vaccine and prescription drug coverage status. METHODS: We used the 2019-2023 National Health Interview Survey and included Medicare beneficiaries aged 65 years and older who enrolled in both Parts A and B or a Medicare Advantage plan. Descriptive statistics were used to examine beneficiaries' characteristics. Logistic regressions were used to examine the associations between the receipt of a herpes zoster vaccine and Medicare prescription drug coverage. RESULTS: The study included 33,578 beneficiaries and 93.5 % of beneficiaries had prescription drug coverage. The prevalence of lacking prescription drug coverage was higher among beneficiaries who did not have a college degree, had family income below the poverty level, had no flu shot and well visit within the past year, and had no usual place for care. The probability of receiving a herpes zoster vaccine was higher among beneficiaries with prescription drug coverage than those without prescription coverage (45.2 % versus 25.3 %). CONCLUSIONS: Herpes zoster vaccination disparities between beneficiaries with and without prescription drug coverage existed before the IRA. Because the IRA only addresses the cost barrier facing by beneficiaries with prescription drug coverage, vaccination disparities was greater after the IRA implementation.