Dr. Donald Berwick’s forced retirement after heading Medicare and Medicaid for 17 months is an unnecessary loss to the country, but his departing advice can help Americans understand how their health system is being improved.

He served on a recess appointment that dodged Senate conformation but expires December 31. President Barack Obama could not renominate him because 42 Republican senators had pledged a successful filibuster. Maine’s two Republican senators, Olympia Snowe and Susan Collins, had the good judgment to stay out of that stampede.

In a final interview with the New York Times, Dr. Berwick said 20 to 30 percent of health spending is a “waste” that yields no benefit to patients.

Waste is a broad term, including needless medical procedures, failure of adequate preventive measures, duplication and inefficiency, as well as outright fraud.

Hospital-acquired infections have caused the deaths of almost 100,000 Americans each year and the illness of millions more, according to the U.S. Centers for Disease Control and Prevention. Dr. Berwick has reported that these complications have added as much as $45 billion a year to hospital costs borne by taxpayers, insurers and customers. He said that some hospitals have virtually eliminated some infections that other hospitals still consider inevitable. Under the Affordable Care Act, sometimes called Obamacare, financial incentives will go to hospitals that excel in fighting these infections starting in 2015.

Unnecessary hospital readmissions add another $12 billion a year, estimates the Medicare Payment Advisory Commission. It says half or more of these readmissions could be prevented through better coordination and patient education, permitting them to recover at home rather than reentering the hospital with complications.

“Integrated care” will also reduce costs, said Dr. Berwick, by protecting patients from having to tell their stories over and over to different providers and letting a doctor know what medication they had already been given. No figure is available for the savings from automated record keeping, but it is becoming substantial.

Preventive medicine is already reducing waste, for example by detecting diseases at early stages for prompt treatment. The Affordable Care Act makes preventive benefits like cholesterol tests, mammograms and screening for colon and rectal cancer free for everyone with Medicare. The new law requires states to provide pregnant women with Medicaid coverage of tobacco-cessation services including counseling and medication.

A new fraud-prevention and enforcement action team has brought Medicare and Medicaid into collaboration with the Justice Department and the Health and Human Services inspector general’s office to prevent, identify and prosecute health care fraud.

Dr. Berwick told the Senate Finance Committee last year that the three goals for improving health care delivery were better care for individuals, better health for populations, and coordinating care for patients journeying though the system: “To be absolutely clear, I am talking about reducing costs while improving the quality of care individuals receive.

Saving money cannot be the primary purpose of the health system, but it can be a helpful side effect of improved medical practices.