Updated

Lawmakers remain at odds over how to address looming Medicare cuts to doctors, and may have to punt until next week despite facing a March 31 deadline.

After that deadline, doctors who take Medicare patients are facing a 24 percent decrease in their federal reimbursements. If those doctors don't get the federal payments, they could opt out – risking the stability of the entire Medicare system.

Patching over those cuts is something Congress does semi-routinely. This is known in Washington short-hand as the “doc fix.”

Because Congress can't come up with a decent funding mechanism, lawmakers have approved 15 such fixes over the past 11 years.

Though Congress was expected to address the issue this week, it might have to wait.

"There's a good chance it could slip," said a senior House GOP aide when asked about the timing.

House Minority Whip Steny Hoyer, D-Md., was critical of the House passing a doc fix two weeks ago which delayed the individual mandate in ObamaCare.

"We ought to just bite the bullet," said Hoyer, who noted that there have been previous delays in getting doctors their Medicare reimbursements.

Senate Majority Leader Harry Reid, D-Nev., told Fox News: "I think it's possible we go this week." But the Nevada Democrat wouldn't commit to moving a bill.

Reid noted that newly minted Senate Finance Committee Chairman Ron Wyden, D-Ore., wants a permanent solution and not another patch.

"They waste time. They waste money," Wyden said, hinting that Congress didn't have to move right away. "The effective deadline is next week. We have time."

A House GOP source said the Monday night deadline is not firm.

"You have a little bit of wiggle room. It's not the end of the world," said a House GOP source. "It gets done within the next week's time."

On the House side, Fox News is told lawmakers are waiting for congressional budget number-crunchers to release an estimate on the cost of the bill. If that comes in soon, there could be a vote later in the week.