The Obama administration distanced itself Wednesday from new standards on breast cancer screening that were recommended this week by a federally appointed task force, saying government insurance programs will continue to cover routine mammograms for women starting at age 40.

As the task force recommendations stirred concern among women and came under fire from lawmakers of both parties, the White House emphasized that they are not binding on either physicians or insurers. Administration officials also fired back against Republicans who argued that the recommendations illustrated the dangers of an expanded government role in medical decision making.

Democrats on Capitol Hill acknowledged that the recommendations, in the midst of negotiations over a health care overhaul, had handed Republicans a vivid new way to raise the specter of rationing.

Kathleen Sebelius, the secretary of health and human services, acknowledged in a statement that the recommendations, by the U.S. Preventive Services Task Force, had "caused a great deal of confusion and worry." She then emphasized that the task force "is an outside independent panel of doctors and scientists who make recommendations" and who neither "set federal policy" nor "determine what services are covered by the federal government."

On the White House blog, Dan Pfeiffer, the deputy communications director, wrote that "women who are currently getting mammograms under Medicare will continue to be able to get them."

The Medicare program, which primarily covers those 65 or older but also insures younger people with disabilities, currently pays for annual mammograms starting at age 40. Coverage policies for Medicaid, the shared state and federal health insurance program for low-income people, are set by the states.

Neither Sebelius nor Pfeiffer explained why the government would not embrace the recommendations from the task force, which is appointed by Sebelius' department.

The task force advised on Monday that most women should not start routine screening until they are 50, as opposed to the current standard of 40. The reason, according to the task force, is that studies show that "the additional benefit gained by starting screening at age 40 years rather than at age 50 years is small, and that moderate harms from screening remain at any age."

Meanwhile, Physician Data Query, the physician group that evaluates new research on cancer screening for the National Cancer Institute, determined that the task force evidence is important enough to be added to information it gives to doctors and the public.