Moreover, the market for health care is distinctive (if not entirely unique) in several key respects. Virtually all of us will need and obtain health care at some point, but we often cannot predict when or in what ways we will need it. And for the vast majority of us, direct payment for the health care services we obtain would be prohibitively expensive. Yet not obtaining needed medical care can be the difference between life and death.

These features help explain why, unlike many other markets, insurance is the overwhelmingly dominant means of payment in the health care market. They also explain why Congress has required that individuals be given emergency care without regard to their ability to pay. As a result, and again unlike other markets, uninsured individuals who are unable to pay directly for needed medical services necessarily shift the cost of those services to others -- to health care providers, the government, individuals with insurance, and taxpayers.

In that way, Congress is not creating a market which it then seeks to regulate. The insurance-based structure of the health care market is already firmly in place. That is why it was well within Congress's discretion to design legislation to operate within, and to address problems posed by, this vast market.