Medicare Part D beneficiaries' self-reported barriers to switching plans and making plan comparisons at all.

In the United States, individuals with disabilities and those aged ≥65 can supplement their Medicare with so-called stand-alone Medicare Part D prescription drug plans. Beneficiaries can switch their stand-alone prescription drug plans annually, but most do not. Indirect evidence has raised concerns that non-switchers do not even make plan comparisons (labeled "inattention"), but direct evidence is scarce. Therefore, we surveyed 439 beneficiaries of Medicare Part D plans from a nationally representative adult sample after the 2024 open-enrollment period. Overall, 53% self-reported making no comparisons. Of those who did not compare, 98% did not switch (vs 67% of those who did compare). Multinomial regressions revealed that beneficiaries who neither compared nor switched were more likely than switchers to report difficulties with comparing and switching, experiencing no plan-related discontinuation, changes, or dissatisfaction, not using advisors or the plan-finder website, and receiving potentially confusing mailings. Non-switchers who did compare were similar to switchers in reporting few difficulties and relying on advisors and the plan-finder website, but they were less likely than switchers to report plan-related changes, discontinuation, or dissatisfaction, while being more likely to report receiving mailings and having no college degree. We discuss insights for policy-making.