Which program specifically involves federal funding only?

Medicare is a program that is specifically funded by the federal government. It provides health insurance primarily for individuals aged 65 and older, as well as for certain younger individuals with disabilities or specific medical conditions. Medicare is entirely federally administered and financed, making it distinct from Medicaid, which is jointly funded by federal and state governments.

In this context, private insurance operates independently of government funding and involves a range of coverage offered by various companies. Therefore, the only program listed that relies solely on federal funding is Medicare. This reflects the nature of how these programs are structured and financed, emphasizing the exclusively federal aspect of Medicare in contrast to the mixed funding model of Medicaid.