Presumably, we will pay with U.S. dollars, which the federal government prints and issues to banks and contractors for goods and services and to retirees who are owed deferred compensation. Since our agents of government are tasked with providing for the welfare of the population and illness and injury threaten welfare, it is only logical that they contract for appropriate surgical and medical care.
Responding to illness and injury is what we might call a disutility, since the object is to get rid of something nobody wants (much like a house fire or flood) and the success of the enterprise is measured in decreased use. This inverse relationship between success and use is what makes disutilities inappropriate for the market. The market relies on increasing use by satsfied customers.
Anyway, the IOUs or letters of credit or credit cards we use to register obligations are incidental. That these IOUs are used by some people for gambling or hoarding or fraud is unfortunate. But, since the quantity available is practically infinite, this misuse of some portion should not be determinative. Congress is to be faulted for claiming that it is. But then Congress also blames terrorists for useless military hardware.