Tomorrow, your doctor may be a corporation.

True, the man or woman with the tongue blade and stethescope will always be a man or woman, prescribing for you, touching you, profoundly or briefly.

He or she may no longer be independent, however, but rather an employe or contractor or in some way part of a corporation that sets many of the rules by which its doctors must work. For example, who they may care for.

Whether or not this will be good for the patient -- or provide a more impersonal, cost-constrained kind of care -- is now a subject of strenuous debate.

For better or worse, more and more doctors, hospitals and clinics are already part of some such arrangement. Their number is growing fast in a phenomenon that is commonly being described as the "industrialization" or "corporatization" or "conglomeration" of medicine.

Or the takeover of "the medical-industrial complex."

In many cases it may also mean health care for profit, paying dividends to investors and showing up on the Big Board with Exxon and IBM.

In 15 years perhaps 20 companies will provide most health care, including their medical and hospital care and health insurance, to six Americans in 10.

This is the prediction of Dr. Paul Ellwood, president of InterStudy, one of the country's most respected health study groups. It was Ellwood who successfully urged the Nixon administration to back the expansion of health maintenance organizations. HMOs hire, contract with or are formed by groups of doctors to give you all of your care for a set monthly fee.

Ellwood predicted the spectacular growth these plans are now seeing. But their growth is only part of the medical upheaval that, by varying predictions, will see most of us being doctored by 10 or 20 or 50 national health care corporations.

Perhaps half of these, it is believed, will be for-profit, investor-owned companies like Humana Inc., the hospital chain that is financing artificial heart operations in Louisville. The other half will be nonprofit groups, like Kaiser and Blue Cross-Blue Shield, which have already begun to expand in the same aggressive, business-like way as the for-profits in order to survive.

Ellwood has a word for all of these groups: "Supermeds."

The incipient Supermeds are already beginning to become conglomerates of hospitals, HMOs, clinics, health insurors and related groups, all expanding, all advertising and marketing like the rest of the business world, and increasingly merging with each other to see who will become the General Motors of health.

Humana, for example, was purely a hospital company until four years ago. It is now selling Humana Care Plus prepaid health care coverage, a health insurance plan that provides full benefits only at Humana-affiliated hospitals. Humana also operates or is getting ready to open 50 Humana MedFirst medical clinics, open seven days a week without appointment; the number will be 200 by Sept. 1. And Humana also owns 86 hospitals with 17,500 beds.

This week Hospital Corp. of America, the world's largest hospital chain, and American Hospital Supply Corp., the largest hospital supply dealer, agreed to one of the biggest mergers in American corporate history.

Such developments are inevitable, Ellwood and others believe. For one thing, they explain, medical care has become so expensive and the cost of medical capital -- buildings, equipment -- so high that only large organizations can afford it.

More important, the United States -- wisely or not, depending on whom you ask -- chose not to go Britain's way to curb health costs: draft doctors and hospitals into a government system with controlled budgets. This left American doctors and hospitals free to proliferate and charge what they pleased, with all costs virtually guaranteed by the government and insurors.

But now all the big payers -- government, insurors, businesses -- want to ratchet down the payments. Business has finally begun to do more than cry about its costly health benefits. Employers are increasingly signing direct contracts with hospitals, HMOs or insurors or using another new tool -- the PPO, or preferred provider organization -- to hold down the cost.

A PPO limits your choice of doctor or hospital. Typically, one or more hospitals and certain doctors agree to care for a firm's employes or a health insuror's clients for a negotiated or discounted price. The affected patients must dig into their pockets for the extra cost if they seek other care.

General Motors recently signed a PPO contract with a group of doctors and hospitals associated as Hospital Care Corp. A Michigan GM worker who goes to one of these doctors or hospitals is fully reimbursed; one who goes elsewhere has to pay 20 percent of the cost.

In the American system, only these mushrooming new organizations seem to have the ability -- and clout -- to begin to ratchet down costly care, especially hospital care, so they can ratchet down prices for the newly tough customers: government, business and health insurors.

PPOs, HMOs, corporate care. This new world is nothing like going to the family doctor above the drugstore.

One hospital in five is now owned or operated (three-fourths of them owned) by an investor-owned firm like Humana and Hospital Corp. of America. This includes 43 percent of all Florida hospitals, 36 percent in Texas, 33 percent in California, 28 percent in Virginia.

Though some, mainly small investor hospitals, are locally owned -- Prince George's Doctors' Hospital in Lanham is an example -- four in five belong to chains that did not begin to exist until the 1960s. And a firm called American Medical International has been making eyes at Prince George's Doctors'.

In the past two years, these chains have bought or contracted to run university teaching hospitals -- the hospitals that set medicine's very pace -- in Newark, Nashville, Louisville, Jackson (Miss.), Wichita, Omaha, Oklahoma City, Denver, Tucson and Los Angeles, where National Medical Enterprises will build a new $100 medical complex for the University of Southern California.

The chains are further dickering with university hospitals in Houston, Irvine (Calif.), Washington -- with George Washington University Hospital -- and Boston, with McLean Hospital, Harvard's psychiatric teaching facility. Harvard doctors fought off an attempt to sell McLean to a chain; now one may take over McLean by contract or lease.

These proud university institutions are to be flagship and showcase hospitals for the chains, which have often been berated for shunning costly teaching and research. But also, says Michael Bromberg, executive director of the Federation of American Hospitals, the commercial hospitals' trade group, they will be the keystones in another new phenomenon: vertical integration into conglomerates that minister to all your health needs.

For the chains are buying or starting HMOs, shopping center clinics and health insurance firms -- in short, starting to become health systems, Ellwood's Supermeds. A University-Supermed Hospital can both lure doctors and patients and provide a place to send the system's sickest patients.

To meet this kind of competition and run just as economically, the traditional nonprofit community hospitals have begun to act in many of the same ways. One in three is now part of a multihospital system, an association or outright chain of hospitals buying drugs and other supplies together, sharing computer systems, combining medical and management expertise. One new such assocation, American Healthcare Systems, joins 233 hospitals with 45,000 beds in 21 states.

HMOs -- systems of doctor, both nonprofit like Kaiser and new profit-making companies like MaxiCare Health Plans, CIGNA Healthplan and HealthAmerica Corp. -- are also exploding in number and coverage. HMO enrollment jumped 22 percent between mid-1983 and mid-1984 and is now more than 16 million.

If growth continues this spectacularly, HMOs and related plans could cover half the population by 1990. Thanks to Kaiser, HMOs already cover 18 percent of the population of California. With a strong push from major employers, HMOs cover 39 percent of the population -- and half of all covered workers -- in the HMO bellwether cities: Minneapolis and St. Paul.

Kaiser, limited to the West just a few years ago, is now in the Washington area, Raleigh-Durham and New York commuterland (Westchester County). It will open soon in Charlotte and Atlanta, and may soon take over HIP, the big Health Insurance Plan of Greater New York, one of the oldest HMOs.

Two commercial health chains, CIGNA and HealthAmerica, are starting or planning Maryland HMOs. HealthAmerica, the largest investor-owned HMO, opened in Baltimore Jan. 1 and plans four centers.

The chains are buying into another phenomenon: the "urgicenters," "surgicenters" and "quick care centers" that have sprung up in business districts and shopping centers. There are 2,500 such mini-clinics -- sometimes dubbed "McDoctors" -- today, 1,400 more than there were a year ago.

"We are seeing a drive toward creation of "centralized empires" in medicine, says Tom Zirkle, a Colorado management consultant. "What is amazing is the accelerated pace."

"Every segment of the industry is concentrating," Ellwood observes. "You see them running together now to form the nucleus of what will be much larger forms . . . The giants are starting to manifest themselves."

And the price competition they are starting will become a competition to survive as fewer hospitals and perhaps many fewer doctors are needed. "Competition" and "marketing" are new medical watchwords.

"I go to hospital meetings and the whole language has changed," Richard J. Davidson, executive vice president of the Maryland Hospital Association, says in an interview in Health Care Management Review. "You would think you were out there with 20 go-go entrepeneurial executives in plastics or the telecommunications field. You listen to the language of market share and marketing the strategic plans to maximize profits . . . It seems to be out of sync . . . I don't hear anybody talking about curing and caring ."

Hospitals, clinics and health plans are advertising. So are some doctors, some with claims as extravagant as a slick used car salesman's. Some are hiring public relations firms and mailing press releases.

"The medical professionals who are the quickest to master the art of marketing will be the survivors," one medical marketing firm says. Its brochure shows a doctor in a white coat. Open the brochure, and he's only half in white and half in a business suit clutching a "Marketing Report."

Is all this good for the patient?

Dr. Arnold Relman, editor of the New England Journal of Medicine, says no. Since 1980, when he wrote his first alarmed editorial about the new "medical-industrial complex" (a term coined in 1969 by Health/PAC, a New York political action committee), he has been a kind of Dr. Paul Revere, warning his colleagues that for-profit and corporate medicine are nigh.

He sees health care, for-profit and nonprofit, increasingly becoming "a commercial product that is marketed and sold for a profit like any other commodity," rather than "a service provided by dedicated people, one of our civilization's critical social functions."

In the new money milieu, he believes, "a significant portion of the population," people who can't afford care, "will be denied access," because "if health care is distributed by income, that's what markets do."

Already, he believes, for-profit hospitals "have carefully positioned themselves to skim" by locating mainly in places where the unpaying poor don't clog their doors. Both nonprofit and for-profit hospitals "dump" uninsured patients onto underfunded public hospitals, he concedes, "but the nonprofits don't do it as much."

He is repelled both by "physician-businessmen" who exploit patients by charging huge fees or pushing marginal or unneeded services, and by physicians who involve themselves financially in medical companies as stockholders, partners or owners -- "medical entrepeneurs." All share the profits determined in part by decisions they make with their patients.

"You can't have good medicine" for any patients, he maintains, "unless doctors work for their patients' interest first, last and foremost. Without this ethical commitment, you can't have good care no matter how good the equipment and techniques, how well trained the doctor.

"The big companies are going to set the conditions under which doctors work. They will hire and fire doctors. They will have increasing economic power over them, and begin to influence the medical profession's values and ethos. The doctor will be either the captive or partner of the corporation, and I think that's going to have an impact on the quality of care."

Disagreeing with Relman on every point, the investor-owned hospitals' Michael Bromberg, one of Washington's ablest lobbyists, replies that:

* The hospital chains all emphasize high-quality care, and studies fail to show any difference in quality of care or performance of doctors between comparable for-profit and nonprofit hospitals.

* It is not through skimming or turning away the poor but through efficient use of people, supplies, equipment and space that the for-profits not only pay taxes -- which the nonprofits do not -- but also earn "a profit on the average of about 5 percent, a margin substantially lower" than that of other health care companies, like drug manufacturers "and, yes, physicians."

* Nonprofit and for-profit hospitals alike must remain competitive and make a profit to survive. The hospital chains have by example been showing the better nonprofit hospitals how to manage themselves, and "our leadership has helped the nation avoid a near-collapse of the health care system."

* As to dumping or shunting the poor to public hospitals, "we do it no more and no less than the nonprofit hospitals."

The best available nationwide statistics so far seem to bear this out. But recent reports from Florida, Texas and Tennessee, states with large numbers of investor-owned hospitals, are said to show major differences, with the for-profits giving less free or charity care. An Institute of Medicine-National Academy of Sciences study group is examining the figures and expects to report late this summer

The American Medical Association once fought what it called "corporate medicine," largely as practiced in consumer-controlled prepaid-care plans, like the long-established Group Health Association here. These plans hired doctors long before the term "HMO" was coined, and the AMA said that disrupted the doctor-patient relationship.

The AMA gradually lost the battle in the courts and the marketplace. More and more AMA members found themselves working on salary or contract. The Nixon administration gave HMOs its blessing. And the AMA forgot its old fight.

Still, at least one current candidate for the AMA's policymaking board of trustees is concerned. He is Dr. Lonnie Bristow of San Pablo, Calif. The biggest problem facing medicine and the AMA, he says, is that government, business and health insurors are trying to turn the credo "healing first and profit second" into "profit first and healing second."

"If the AMA is not successful" in addressing this, says Bristow, a past president of the American Society of Internal Medicine, doctors "will be relegated to the role of tradesmen, and the party that suffers the greatest loss will be the American public."

This would disturb Dr. Paul Ellwood too. There must be competition, he says, but "the competition must be around quality," good care for all patients, as well as price, and also around "access," giving care to everyone.

"Relman is being helpful," he says. "He's saying things we have to say. He's made the profit side much more sensitive to the quality of care they're delivering."

But if medical care is to be delivered economically, change and consolidation are unavoidable, he says. "Every doctor is going to have to join something . . . The revolution is under way. There's no stopping it. You can't turn it back."

In an article in Health Affairs, Chicago health care consultant Jeff Goldsmith describes rather than damns the changing health establishment as "a vital, active enterprise in the midst of revolutionary change."

"Powerful economic forces are reshaping the U.S. health care system in a way that will cause it to diverge increasingly from the centrally managed, national health care systems in other countries," he writes. Rather than try to supplant the new marketplace forces, he says, government policymakers -- and society -- should turn their attention to two challenges that the marketplace cannot solve:

* Making sure care is both humane and economically prudent.

* Devising "a humane, responsible system" for financing the care of the poor and uninsured.

This last is the one point on which Relman, Bromberg and virtually everyone else in the health world agree. Whatever its other pluses or minuses, too many of the poor are indeed being shut out of Medicine, Inc.