The point isn't (just) that people should get lifesaving treatment even if they can't afford it, it's (also) that people in life-threatening situations can have

The point isn't (just) that people should get lifesaving treatment even if they can't afford it, it's (also) that people in life-threatening situations can have a hard time proving that they're capable of paying even when they are. For example: A man's been hit by a car. The driver calls 911. Do you send an ambulance? An ambulance arrives. The medical team springs into action, and one of their number looks through the stricken man's wallet for proof of insurance. He doesn't find any. Do you discontinue care? Suppose instead that he finds an insurance card, but it's stained with blood; a reasonable person couldn't use it to tell whether the injured man's insurance was up to date. Do you discontinue care? A little imagination should supply you with many similar scenarios. One could invent a method of proving insurance (or assets) both quick and powerful enough to address them all (a universal database keyed to DNA, perhaps), but certainly nothing like that exists today.