WASHINGTON — The American medical system squanders 30 cents of every dollar spent on health care, according to new calculations by the respected Institute of Medicine. But in all that waste and misuse, policy experts and economists see a significant opportunity — a way to curb runaway health spending, to improve medical outcomes and even to put the economy on sounder footing.

“Everybody from Paul Krugman to Paul Ryan agrees it is essential to restrain costs,” said Dr. Mark D. Smith, the president of the California HealthCare Foundation and the chairman of the committee that wrote the report, referring to the liberal economist and Op-Ed columnist for The New York Times, and the conservative Wisconsin congressman who is Mitt Romney’s vice-presidential running mate. “The health care industry agrees, too.”

The Institute of Medicine report — its research led by 18 best-of-class clinicians, policy experts and business leaders — details how the American medical system wastes an estimated $750 billion a year while failing to deliver reliable, top-notch care. That is roughly equivalent to the annual cost of health coverage for 150 million workers, or the budget of the Defense Department, or the 2008 bank bailout.

The institute’s analysis of 2009 data shows $210 billion spent on unnecessary services, like repeated tests, and $130 billion spent on inefficiently delivered services, like a scan performed in a hospital rather than an outpatient center.