Health care is a scarce resource.

An excerpt (just one paragraph) from an article by Peter Singer in the New York Times:

"Health care is a scarce resource, and all scarce resources are rationed in one way or another. In the United States, most health care is privately financed, and so most rationing is by price: you get what you, or your employer, can afford to insure you for. But our current system of employer-financed health insurance exists only because the federal government encouraged it by making the premiums tax deductible. That is, in effect, a more than $200 billion government subsidy for health care. In the public sector, primarily Medicare, Medicaid and hospital emergency rooms, health care is rationed by long waits, high patient copayment requirements, low payments to doctors that discourage some from serving public patients and limits on payments to hospitals."