“…Of those with original Fee-For-Service Medicare coverage (approximately 34 million Americans), it has been estimated that most (91%) have some form of supplement coverage to defray the outof-pocket expenses from copayments, coinsurance, and deductibles that Medicare does not cover. For example, a recent study showed that 39% had employer-sponsored Medigap coverage, 27% purchased Medigap coverage, 17% had Medicaid coverage, and 7% had other nonMedicare coverage that could be used to offset at least some of Medicare's out-of-pocket payment requirements [17]. The number of Medicare beneficiaries who purchase Medigap coverage is large, and demographics, socioeconomics, health status, and benefit levels likely differ for them versus those without such coverage; thus, the prevalence of UI and its impact on quality of life may differ for those with Medigap as well.…”