The alleged right to medical care is one instance of a broader category known as welfare rights. Welfare rights in general are rights to goods: for example, a right to food, shelter, education, a job, etc. This is one basic way in which they are quite different from liberty rights, which are rights to freedom of action, but don't guarantee that one will succeed in obtaining any particular good one may be seeking.
If I have such a right, some other person or group has the involuntary, unchosen obligation to provide it.
Moderate my tush........