WASHINGTON — President Obama says the primary goal of health reform is to rein in runaway spending, and he points to real-world examples in which doctors and hospitals have improved care and reduced costs.

Making the leap from a handful of success stories to restructuring one-sixth of the nation's economy — and writing it all in legislative language — is something he hasn't figured out how to accomplish.

The proposals circulating in Congress make strides toward curbing medical spending, largely by grabbing what Len Nichols of the nonpartisan New America Foundation calls the "low-hanging fruit." The bills extract savings by targeting medical errors, administrative waste and unnecessary duplication — money that would be reallocated to cover some of the 47 million uninsured.

But a variety of experts say the legislation lacks the more far-reaching structural changes needed to ensure that, over the long term, the nation gets its money's worth.

"The truth is that we don't know today all of the steps that are necessary to move toward providing higher-quality, lower-cost care," White House budget chief Peter Orszag recently told the Council on Foreign Relations.

As health care consumes more and more of the total economy, it reduces the money available for other expenditures. The question is whether Americans are getting a good return on the investment.

Achieving Obama's goal, say Orszag and other experts, requires covering every American, digitizing medical records, encouraging healthy behaviors and, perhaps most important, paying medical teams to deliver evidence-based care rather than highest volume. It means focusing on chronic illnesses, reducing costly hospital and specialist visits, and nudging doctors to work in teams.

Combined, those strategies "represent our best chance of creating a health care system" that delivers value but does not bankrupt the nation, Orszag said.

In the past, Congress has framed health reform as a moral imperative to cover everyone. The Obama team approaches it as an economic issue, noting that $1 of every $6 spent in America goes to health care. If nothing changes, it will be $1 of every $5 by 2017.

It isn't the amount of money that is the problem, said former Bush administration official Mark McClellan — it's what we get for it. "If we're living longer, better lives, that health care spending is a good thing," he said. "The problem is that a lot of that spending is not leading to productive improvements in the quality of life."

Health systems such as Intermountain Healthcare in Utah, the Billings Clinic in Montana and Gundersen Lutheran in Wisconsin have brought growth under control while delivering superior care. It did not come easily.

Number crunchers at Intermountain found that reducing the number of caesarean sections it performs from 21 percent of births to 19 percent would save patients and insurers $8 million but cost Intermountain $1.8 million, said vice president Brent James.

David Kendall, a senior fellow at the nonpartisan Third Way think tank, notes that one out of every 10 health care dollars spent in the U.S. is directly attributed to diabetes. Pilot projects have found that paying a medical team for total care — monitoring blood-sugar levels, giving eye and foot exams — rather than paying for separate visits to an ophthalmologist or podiatrist is better for the patient and costs less.

"The financial losers will be hospitals that no longer amputate somebody's foot or the dialysis centers" that are no longer needed, he said. "That's where we save a lot of money."

Dick Davidson, a former president of the American Hospital Association who helped defeat the Clinton administration's health care plan, said Obama "has had enormous courage" in pushing for major changes.

"People say, 'Slow down, slow down,' but that's what policymakers in Washington always say," he said. "If he misses this opportunity, he's not going to have another one."