WASHINGTON (AP) — The Obama administration is trying to disentangle itself from another controversy over Medicare coverage. Amputees are protesting this time, fearing they'll be denied the latest technology for artificial legs and feet.

Medicare spending for those items soared in the last 10 years, even as the number of amputees declined because of improved diabetes care. That prompted scrutiny from government investigators.

Recently, Medicare's billing contractors proposed closer medical supervision of the independent technicians who sell and fit artificial limbs, as well as tighter rules for patients to qualify for high-tech devices that can cost as much as a car. The proposal is technical, but industry says it would translate to diminished quality of life for beneficiaries.

The move launched an industry-backed protest that attracted support from a Boston Marathon bombing survivor and a former U.S. senator who lost a leg in wartime service.

As sign-waving amputees demonstrated in front of the Health and Human Services headquarters in Washington on Wednesday, administration officials held a private meeting with their representatives.

Tom Fise, an industry official who participated, said the administration "underscored that cost and financial concerns are not an appropriate basis for writing or changing" Medicare coverage policies.

A Medicare spokesman said the agency is following up with the billing contractors. In a statement, Medicare said it believes that "beneficiaries will continue to have access to lower-limb prosthetics that are appropriate," and the payment overhaul "is not meant to restrict any medically necessary prosthesis."

Joining the demonstration was Boston Marathon bombing survivor Adrianne Haslet-Davis. Although far too young for Medicare, the ballroom dancer and motivational speaker said it's a cause "close to my heart."

"I'm here because America rallied around Boston, and I'm rallying around America," said Haslet-Davis, who lost her left leg below the knee.

Weighing in via a letter to HHS leadership was former Sen. Bob Kerrey. The Nebraska Democrat was awarded the Medal of Honor for combat in Vietnam, on a mission in which he continued directing his Navy SEAL unit after he was gravely wounded. He lost his right leg below the knee.

"They are attacking a problem that is nonexistent," Kerrey said in a telephone interview. "If you have a problem provider, shut him down; kick him out of the program. Why make it difficult for everybody else?"

The campaign is being led by the American Orthotic & Prosthetic Association, a trade group, alongside a broader amputee coalition that includes patients. Haslet-Davis and Kerrey said they are not being paid for their advocacy.

The industry group has several objections that involve emotionally charged issues and hinge on concerns about how the technical language of the proposal would be applied in real life. For example:

—An amputee who uses a cane, crutch or walker for limited purposes, such as getting out of bed at night to use the bathroom, will be limited to older-model artificial legs that are less functional. That particular example appears nowhere in the proposed policy, but industry official Fise — AOPA's executive director — said he could see a scenario in which a Medicare billing reviewer would deny payment for an advanced prosthesis if the program had previously paid for a cane or walker for the same patient.

—A requirement that artificial legs and feet provide "the appearance of a natural gait" is being questioned as vague, unscientific and potentially restrictive. "There is no normal gait," said Dr. David Armstrong, a professor of surgery at the University of Arizona and diabetes expert. "That's just like saying there is a normal eye color." Armstrong serves as an unpaid medical adviser to the amputee coalition.

Although artificial legs and feet are a small part of Medicare's $600-billion-a-year expenditures, a 2011 inspector general's report found that Medicare spending for lower limb prostheses increased by 27 percent from 2005 to 2009, even as the number of beneficiaries getting them decreased by about 2,000 people. During those years, spending went up from $517 million to $655 million. The report also documented questionable billings.

Fise, the trade group executive, says that the industry has already addressed the inspector general's concerns, and Medicare spending on artificial limbs has gone down since the report.

The Obama administration has been sensitive to the political implications of Medicare policies since the outcry over baseless allegations that a provision in the president's health care law to pay doctors for end-of-life counseling would lead to "death panels." That proposal was cut from the draft law and only recently reinstated through regulations, long after the controversy faded.

A public comment period on the proposed coverage changes for artificial legs and feet closes Monday. It's unclear when a final policy will be issued.