Which of these is NOT a qualifying event for Medicare?

The reason falling below the federal poverty level is not considered a qualifying event for Medicare is that Medicare eligibility is determined by specific criteria established by the Centers for Medicare & Medicaid Services (CMS), which do not directly relate to an individual's income level.

Medicare is primarily designed for individuals aged 65 and older, those who have been receiving Social Security Disability Insurance (SSDI) for at least 24 months, and individuals with end-stage renal disease (ESRD). These criteria clearly define the qualifying events for Medicare eligibility. In contrast, income level considerations, such as falling below the federal poverty level, may affect eligibility for programs like Medicaid or assistance programs but do not impact Medicare eligibility directly. Consequently, the other options represent specific situations that indeed qualify an individual for Medicare coverage.