The goal of the Affordable Care Act is to make affordable, quality health care coverage available to more Americans. But how many physicians will America need to satisfy this new demand?

The debate over doctor supply rages on with very little conclusive evidence to prove one case or the other.

Those experts who see a shortage point to America’s aging population — and their growing medical needs — as evidence of a looming dearth in doctors. Many suggest this shortage already exists, particularly in rural and inner city areas. And still others note America maintains a lower ratio of physicians compared to its European counterparts.

This combination of factors led the Association Of American of Medical Colleges to project a physician shortage of more than 90,000 by 2020.

On the other side of the argument are health policy experts who believe the answer isn’t in ratcheting up the nation’s physician count. It’s in eliminating unnecessary care while improving overall productivity.

The solution, they say, exists in the shift away from fee-for-service solo practices to more group practices, away from manually kept medical records to electronic medical records (EMR), and away from avoidable office visits to increased virtual visits through mobile and video technologies. Meanwhile, they note physicians could further increase productivity by using both licensed and unlicensed staff, as well as encouraging patient self-care where appropriate.

The doctor divide: Global and domestic insights

Among the 34 member countries of the Organization for Economic Co-operation and Development (OECD), the U.S. ranks 30th in total medical graduates and 20th in practicing physicians per 1,000 people.

Despite these pedestrian totals, there is one area where the U.S. dominates. It ranks first in the proportion of specialists to generalists– and there’s not a close second.

These figures don’t resolve the debate on America’s need for physicians but they do reveal an important rift in the ratio of U.S. specialists to primary care practitioners.

And while these totals shed some light on where the U.S. stands globally, there’s still widespread disagreement within our borders on a very straightforward question: How many practicing physicians are there in America?

The cause of confusion is that not all licensed physicians practice clinical medicine and, among those who do, the number of hours spent in clinical practice is unknown.

In California, for example, the AMA and the Medical Board of California disagree heavily on the number of practicing physicians. The difference in their estimates is nearly 20 percent.

Further, the distribution of licensed doctors varies significantly within and across our states. California’s greater Bay Area hosts approximately 30 percent more medical specialists than Los Angeles. And the number of active physicians per 100,000 population in Massachusetts is roughly twice that of Mississippi.

In the absence of conclusive data and in the face of so much uncertainty, is it possible to determine whether we have too many physicians, too few or just enough?

Turning the debate upside down

As the number of insured people in the U.S. grows rapidly, our nation will face a shortage of physicians — unless there’s (a) an immediate uptick in their numbers or (b) a drastic change in how the majority of physicians practice.

For this reason, it may seem logical to begin training some 90,000 new physicians.

But the costs would be too enormous and the lag-time too substantial to meet America’s pressing demand. Not to mention the costs created by more physicians, more offices and more support staff.

To put it bluntly, the U.S. can’t afford the number of physicians it would need in today’s inefficient health care delivery system.

If we want to address the increased demand for health care services while keeping health care affordable, we need to make our system 10 to 20 percent more efficient. Once we do that, we will have enough physicians — not only for today but for tomorrow, as well.

As a nation, we can continue to debate whether or not we need more physicians. But we’d be better off transforming the process of care delivery. In reality, that’s our only choice.

Robert Pearl is a physician and CEO, The Permanente Medical Group. This article originally appeared on Forbes.com.