IRS Commissioner John Koskinen said furloughs — forced unpaid days off for employees as part of an IRS closure — is one idea reluctantly being tossed about to save money, though they are hoping they will not have to go there.

People call it furloughs; I view it as: Are we going to have to shut the place down? And at this point, that will be the last thing we do, … but there is no way we can say right now that that wont happen," Koskinen told reporters at a Thursday press conference on the upcoming tax season. "Again, I would stress that would be the last option."

He said a shutdown would mean the IRS would "close the agency for a day, two days, whatever days it would take to close the gap that we can't otherwise close in a reasonable way."