Doctors who treat Medicare patients will see their pay cut by 21.3 percent after Congress failed to approve a fix to the government insurance program for the elderly and disabled.

The Senate on Friday passed legislation that aims to delay the pay cuts until the end of November, but the House of Representatives will not vote on the payment fix until next week.

Lawmakers did not act before the agency that oversees Medicare ordered Friday that claims submitted this month by doctors, nurse practitioners, therapists and others be paid at the lower rate.

The pay cuts may be temporary. If the House passes the payment fix next week, medical professionals who are paid under the physician fee schedule will be able to resubmit claims and be paid at the higher rate.

Still, Arizona doctors say Congress' inaction over the payment-fix issue will harm both the medical community and more than 900,000 Arizona residents who are enrolled in Medicare.

"I truly never thought we would see the day right now where the Congress would allow (reimbursement cuts) to become law," said Chic Older, vice president of the Arizona Medical Association, a doctors group. "It's just crazy to think Congress would do this."

Doctors groups said that even a temporary payment cut sends a bad message to doctors and seniors.

Doctors have long complained that Medicare reimbursement rates do not keep up with the actual cost of taking care of patients.

Now with the cuts, more doctors may decide to no longer care for Medicare patients, said Jeffrey Wolfrey, president of the Arizona Academy of Family Physicians. Arizona already has a shortage of primary-care physicians who handle basic medical checkups.

"We've never had a litmus test like this," Wolfrey said of the Medicare cuts. "I think we'll see an increase in physicians who will stop seeing Medicare (patients) altogether."

The Medicare payment cuts are required under a 1990s-era budget law that Congress has waived each year before pay cuts took effects. Yet with heightened angst this year over spiraling budget deficits, Congress did not act before Medicare began processing claims at the lower rate.

Bills submitted by doctors since June 1 will be paid at the reduced rate. An earlier congressional reprieve expired May 31. Medicare had been holding off on processing claims in the hopes lawmakers would act, but the agency said it can no longer do that without hurting doctors' cash flow.

What's more, Medicare worried about paying the cost of processing those claims at one rate, only to have to reprocess those claims once Congress approves a different rate.

The federal agency will likely have to reprocess those claims once Congress acts, but the federal agency decided it could no longer wait for Congress, a spokesman said.

The agency processes 4.4 million payment claims each day.

The bill passed Friday by the Senate delays the cuts until the end of November - after congressional elections - when lawmakers hope the political climate is better for passing a more permanent, and expensive, solution.

The bill would also increase payments to providers by 2.2 percent. The legislation would cost more than $6.4 billon over 10 years, and it would be paid with a series of health-care and pension changes agreed upon by both Democrats and Republicans.

Bill Thrift, a Prescott physician who no longer sees new Medicare patients, said doctors with large numbers of Medicare patients will be squeezed financially until Congress acts.

He estimates that he is paid about $50 for each office visit from a Medicare patient. With the 21 percent cut, Thrift will get less than $40 per visit. That is not enough to pay for his overhead costs such as office staff, medical equipment, insurance and office-leasing costs, he said.

Thrift said he also worries that private insurance companies may also seek to slash reimbursement for doctors. Private insurers often piggyback their payment rates based on Medicare-payment rates.

"They (lawmakers) can't figure out that, as technology increases, so does the cost of medicine," Thrift said. "They are trying to squeeze the savings out of doctors and hospitals."

The Associated Press contributed to this article.