Which individual would not be eligible for Medicare?

The reasoning behind the ineligibility of the individual in question largely hinges on the age requirement and the relationship to someone who is already covered by Medicare. Medicare eligibility primarily extends to individuals who are aged 65 and older or those who have specific disabilities.

In this case, Joan, who is 60 years old, does not meet the minimum age requirement of 65 to qualify for Medicare on her own. Although she may be related to someone who is covered by Medicare, having a spouse enrolled in the program does not grant her any entitlement to benefits unless she herself reaches the qualifying age or meets other specific conditions, such as having a qualifying disability.

In contrast, the other individuals mentioned are either already covered by Medicare, have reached the qualifying age, or are receiving benefits based on disability, which aligns with the criteria set forth for eligibility. Therefore, Joan stands out as the only individual in this question lacking the necessary age qualification for Medicare.