Federal agencies were preparing Thursday for the possibility of a government shutdown if Congress doesn't pass a budget before midnight. The Office of Management and Budget (OMB) held a conference call Thursday afternoon to discuss contingency planning in case of a shutdown like the U.S. had in October 2013.

None of the agency contingency plans posted on the OMB website had been updated this year. A shutdown is unlikely, POLITICO reported, but OMB was readying itself just in case. 

"Congress is taking a series of actions today on legislation that would prevent a lapse in appropriations and allow for continued Government operations," an OMB official wrote in an email to International Business Times. "We continue to believe that time remains for Congress to pass full-year appropriations for FY 2015, and prevent a government shutdown. However, out of an abundance of caution, we are working with agencies and taking steps to prepare for all contingencies, including a potential lapse in funding."

The OMB will start asking agencies to cease operations if midnight passes and it looks like no agreement is likely, Time reported.

The most recent government shutdown took place for 16 days in October 2013. About 850,000 government employees were furloughed at its peak, according to an OMB report, and the lost productivity amounted to $2 billion. All 401 national parks closed, small business contracts dropped and Food and Drug Administration examinations were delayed.

There have been 18 government shutdowns since 1976. October 2013's 16-day funding gap was the third-longest, beaten out by the 18-day gap in 1978 and the 21-day gap in 1995-1996.

The 1995-1996 shutdown took place over the holidays, which the U.S. could see if Congress does not pass this year's omnibus bill by midnight. 

"A Christmas shutdown is not a good idea," President Barack Obama said earlier this week. "We need the outgoing Congress to pass a budget and keep our government open."