Sign displayed at the Justice Department after the government reopened on Monday January 28, 2019. (CNN/ Laura Jarrett)
Washington CNN —  

Thousands of federal workers came back to their posts on Monday, returning to a deluge of missed emails and a month of work to catch up on after the end of the longest government shutdown on record.

From President Donald Trump’s decision on Friday to end the shutdown on through Monday, federal agencies issued statements to let workers know how the reopening would go, how they could get their accounts to work again – and how they would get paid.

Food and Drug Administration commissioner Scott Gottlieb posted a thread on Twitter for FDA workers having technology issues, appearing to brace for employee badges not working.

A US Forest Service regional office echoed other offices across government in its welcome back message that it knew it would take “a little time and patience to regain computer access and begin project work.”

‘Patience and perseverance’

While some facilities needed time to reopen, some department heads and managers tried to welcome workers back into normalcy as the morning kicked off.

A sign warned people headed for the Justice Department’s cafeteria Monday morning that “the recent situation” meant it would take time to get the cafeteria fully back in operation.

Housing and Urban Development Secretary Ben Carson addressed HUD workers on Monday, according to his spokesman Raffi Williams, and thanked them for “patience and perseverance.”

“Today, as you dust off your desks, get your PIV, pins and passwords working, please take time to commiserate and check on your colleagues,” Carson’s remarks read. “And gather your thoughts on what your priorities should be.”

Emily Lewis, who works at NASA’s Shared Services Center in Mississippi, told CNN on Monday afternoon that workers had been “anxious to get back,” but that management held a breakfast with employees and lessened worry around getting back to work. Lewis stressed a degree of support within the entity as well.

“It’s not like a bunch of people took a vacation willingly at one time,” she said. “We all know the situation we are collectively in.”

Lewis added that with uncertainty around funding being extended past three weeks, just as they had to start work back up, they had to keep in mind the possibility they could have to shut back down.

“It’s almost like stepping on ice, not (knowing) how long it will hold,” Lewis said.

Glenn Fitzpatrick, a federal contractor at the Pipeline and Hazardous Materials Safety Administration, told CNN that he and other contractors worked remotely on Monday once their stop work order was over and they could access federal systems again.

“It’s just been slammed all day,” he said.

Fitzpatrick said he did not have issues getting back into their systems, but noted the particular pressure the shutdown placed on contractors, who were not guaranteed full back pay.

WMATA, the public transit authority in Washington, welcomed back federal workers, whose resuming schedule on Monday was expected to ensure trains were full again after a few weeks of roomier Metro cars.

A preliminary estimate from WMATA during the shutdown said the Washington area subway system had a 16% drop in ridership while agencies were closed compared to average levels prior to the shutdown.

Welcome back and backpay

Other agencies, like US Customs and Border Protection, had mostly stayed working through the shutdown, with employees unpaid and some growing anxious about when their next paycheck would come.

US Customs and Border Protection commissioner Kevin McAleenan issued a statement to the CBP workforce saying his team had worked to process time cards and that they were “working aggressively to make sure you are paid as soon as possible.”

Department of Homeland Security spokesman Tyler Houlton said in a statement Friday that “nearly 90%” of DHS employees had worked without pay through the shutdown and anticipated employees would “be receiving paychecks soon.”

According to the American Immigration Lawyers Association, immigration courts were expecting confusion on Monday. The group said it was told by the Executive Office for Immigration Review on Friday that “there will likely be some confusion and disorganization at first, so we are asking all parties to be patient as we restart operations.”

And other departments and advocates hailed the reopening for workers who were returning to work after the long shutdown, thanking them and the community.

CNN’s Gregory Wallace, Ellie Kaufman, Priscilla Alvarez, Geneva Sands and Laura Jarrett contributed to this report.