If there is one thing that both parties can agree on in the health overhaul debate, it’s the need to build a health system that promotes prevention rather than just manages disease.

To do that, legislation being debated in Congress requires Medicare and private health insurers to fully cover preventive services such as checkups and screening tests for cancer without any patient co-payments or deductibles. Saying prevention measures can save lives and limit health spending, President Barack Obama has cited such a provision as one of the eight consumer protections he wants in any health overhaul legislation.

But while they support preventive measures, some insurance and health officials caution that encouraging more prevention will not save money. The health insurance industry-despite recent moves to offer plans that eliminate patient cost sharing for preventive services-is balking at the congressional mandate. Officials say such a provision would lead to higher premiums and hamper insurers’ flexibility to design plans.

Moreover, while consumer groups, health experts and advocates for seniors applaud removing financial hurdles to preventive services, some health experts caution that not all preventive services have been proven to save lives, and even fewer can limit health spending.

“In the field of prevention, few areas save a lot of lives and money,” Dr. Barnett Kramer, associate director for disease prevention at the National Institutes of Health, said in an interview. While most childhood immunizations and smoking cessation programs are cost-efficient, the answer is less clear for screenings for breast and cervical cancer, he said. He stressed that screening tests such as these can still be worthwhile in saving lives, even though they may not save money over the long run.

The value of a widespread prostate cancer screening was questioned Friday by the top medical officer for the American Cancer Society. “Screening does not clearly save lives and many men who get aggressive treatment clearly do not need aggressive treatment,” Dr. Otis W. Brawley said in response to the announcement that Sen. Christopher Dodd, D-Conn., has prostate cancer. He stressed that men should know the risks and benefits of screening for the disease.

The Congressional Budget Office also noted the lack of savings. In its analysis of the House bill, the CBO says there would not be a cost savings from the removal of copayments or deductibles for preventive services. Instead, it says the provision will cost Medicare $2.8 billion over the next decade. Another provision in the House bill that would require the state-federal Medicaid program to cover preventive services would cost an additional $7.1 billion over a decade, the CBO has estimated.

Under the House plan, patients could receive free an initial physical exam, diabetes screening tests, blood tests for heart disease, mammography, pap smears, bone mass measurements, flu and pneumonia vaccines, screenings for colon and rectal cancer, and ultrasound screenings for abdominal aortic aneurysm. It would also require insurers to waive cost sharing for preventive services recommended by a national task force.

The bill passed by the Senate Health, Education, Labor and Pension Committee includes similar mandates.

“This is one way to knock down barriers for patients accessing preventive services,” said Paul Bonta, associate executive director of the American College of Preventive Medicine. “This is a big deal as we’ve worked for a number of years to increase the availability of preventive services.”

In another legislative attempt to focus national attention on prevention, a draft Senate overhaul bill would provide up to $10 billion annually for a “prevention and public health investment fund” — money which could be used for various projects, such as bike paths and farmers markets to promote fitness and healthy eating.

Studies have shown that requiring even small copayments can deter patients from prevention screenings. A Brown University study published last year in the New England Journal of Medicine showed that the number of women getting mammograms fell 8 percent when the women had to pay $12 for the screening test.

Health plans appear to be getting the message that to encourage prevention they should make the tests free.

Aetna, one of the nation’s largest insurers, this year began introducing health plans for small employers that charge patients no co-pays for preventive care such as routine physicals, vision and gynecological exams, and well-child visits.

The company says it is pricing that new plan the same or nearly the same as what the existing plans would have cost, although it has increased co-pays on certain other benefits.

Aetna spokesman Mohit Ghose on Friday said the company strongly supports efforts to promote prevention in health reform. He declined to say whether the company would support a government mandate eliminating copayments for preventive services.

America’s Health Insurance Plans, the industry’s top lobbying group, opposes the mandate, said spokesman Robert Zirkelbach. He cited the need to give insurers flexibility in designing benefit packages.

Wellpoint, the largest Blue Cross and Blue Shield company, said it sees the benefit for waiving cost sharing but doesn’t want the government mandate.

“Many of WellPoint’s affiliated health plans’ benefits already offer preventive services with no co-pay or deductible as we feel these are important services,” said spokeswoman Cheryl Leamon. “We also believe it is important for our members and others to have the choice in the type of health plan and benefits that fit their needs.”