A question often heard in the debate about health care reform is whether it will be possible to achieve significant cost savings without rationing health care services.

It is the wrong question. Health care rationing already occurs in the Unites States and in every other country as well.

There are at least eight explicit and implicit categories of health care rationing. Here are examples of rationing types, starting with the explicit:

By age. This occurs most notoriously in the United Kingdom, where, for example, it is rare for anyone over the age of 55 to receive hemodialysis for kidney failure. Even in the United Kingdom, rationing by age is not discussed openly but is a gentlemen's agreement among physicians stemming from a sense of finite resources and infinite demand.

By prognosis. Rationing by prognosis -- selecting for treatment those with the best chance of responding to care -- is a common feature of medical practice in Europe. In the United States, it has been limited to conditions such as third-degree burns where it is known with a great degree of precision that injury over a certain percentage of the body invariably proves fatal. The frequency with which clinical decisions are challenged by lawsuits in the United States is one reason why rationing by prognosis is not common here.

By coverage. This is the most common form of explicit rationing in this country. Most health insurance plans omit certain forms of medical care, such as cosmetic surgery. Plans often limit benefits such as number of hospitals days or home care.

By scarcity. In the United States, rationing by scarcity occurs most often among insured patients when the intensive care unit is filled. In those cases, the prognosis usually determines who gets the next bed. In all nations, of course, the scarcity of available organs for transplant results in rationing.

There are also examples of implicit rationing:

By budget. The demand for medical care typically exceeds the supply. In the United States, health maintenance organizations constrain supply more than in the fee-for-service sector. Waits are common, though much shorter than in the United Kingdom. The constraints result because the capitation payments that finance many HMOs set a budget for the organization, in contrast to the open-ended nature of fee-for-service funding.

By price. This is the most common form of implicit medical care rationing in the United States. It is not used as often in other developed countries. People without medical insurance clearly face rationing by price. Those with insurance face it when services such as most nursing home care, cosmetic surgery and infertility treatment are not covered under their health insurance plan.

By queue. Rationing by queue occurs commonly in other countries because of budget constraints. This postpones consumption of the service being rationed such as a diagnostic test or elective surgery. The extent of waiting lists for surgery in Canada and elsewhere and the hardships imposed by such delays are commonly cited in the current debates. In the United States, rationing by queue takes place most commonly through two circumstances -- HMOs and organ system transplants.

By hassle. This is a variant of rationing by queue. In this case, administrative barriers are placed between the doctor-patient relationship and the actual delivery of services. A recent article in the New England Journal of Medicine describes these third-party insurance maneuvers as occurring when "armies of claims clerks, administrators, auditors, form processors, peer reviewers, functionaries and technocrats ... insinuate themselves into a complex system that authorizes, delivers and pays for medical services." It is my impression that rationing by hassle is a uniquely American phenomenon.

Thus, the question is not whether rationing will occur. It is already here. Our goal should be to minimize rationing by using resources as efficiently and equitably as possible. The American public needs to educate itself to make fair and difficult choices about the consumption of health care because no nation, not even one as wealthy as ours, can afford to pay for all the health care the public would like to consume.

The United States has difficulties in confronting health care rationing. We have deluded ourselves by rationing -- for the most part -- implicitly, while contending that rationing occurs in other countries, not in our own.

As the escalating costs of medical care tear at the veil that covers our rationing processes, we face the need for openly discussing difficult choices. It's time to start that conversation.

The writer, a general internist, is president of the Robert Wood Johnson Foundation of Princeton, N.J., a nonprofit health care philanthropy.