While I don't disagree in principle, this is impossible to enact. Consider the case where this person who has chosen not to have insurance is in a car accident and render incapable of communicating. Responders and those at the hospital must act under the assumption that the victim has insurance and do everything in their power to save them.
In this situation the person in the accident can later claim that they didn't want to be saved and thus owe nothing. We, that is the rest of us who participate, are then forced to carry this cost and they free ride.
In this situation the person in the accident can later claim that they didn't want to be saved and thus owe nothing. We, that is the rest of us who participate, are then forced to carry this cost and they free ride.