You should tell Mrs. Radford that Medicare Advantage generally does not have a lot of extra special eligibility hurdles beyond regular Medicare, but she must meet a few key conditions. In plain terms, to join a Medicare Advantage (Part C) plan, she must:

  1. Be eligible for and enrolled in both Medicare Part A and Part B.
  2. Live in the plan’s service area (the geographic area where that specific plan is offered).
  3. Be a U.S. citizen or lawfully present in the United States.

If her question is from a training/quiz context, the best concise answer is:

She must be enrolled in Medicare Parts A and B, reside in the plan’s service area, and be a U.S. citizen or lawfully present; there are no additional health‑based eligibility requirements.