Approximately 800,000 federal government employees have gone without pay since the third government shutdown of the year went into effect just after midnight on December 22.

A portion of these workers are employed as contractors, which means their payments come from a third party. If the government is not working with that third party, those workers may not be paid.

Julie Burr, an administrative assistant at the US Department of Transportation in Kansas City, Missouri, was told in an email that she had to return her work computer to her office because the government was shutting down. As a contractor, she can't work until the shutdown ends.

Burr, a single mother to a 14-year-old boy, panicked.

"I want to get back to work as quickly as possible, not only because of the paycheck, but I love what I do," she told INSIDER.

"I know that there's probably gonna be a lot of work waiting for me, and it's going to take some time to catch up when we get back."

She is now one of thousands of federal government employees who are officially jobless as the third US government shutdown of 2018 continues. But unlike many workers who are employed directly by the government, Burr is a contractor, meaning her paycheck comes from a third-party business hired by the government. If the government stops doing business with the third-party company, the employees don't get paid.

Unlike Burr, some of her coworkers at the transportation agency are direct employees, so they could get back pay, eventually. As a contractor, Burr does not have the same security.

"My contracting company does not pay me for any days that are not worked," she said.

To make up for the lost income, she has picked up extra shifts at her second job at her local Barnes & Noble book store. Reached by phone on Wednesday during a break from her shift, Burr said she was "really hoping" that Congress and President Donald Trump "would come to a conclusion" instead of shutting down the government.

"I was getting my fingers crossed and then it didn't happen," she said. Now, she said, she can only hope Congress will reach an agreement soon and the shutdown won't last as long as the last one.

"It needs to be resolved as soon as possible because there are a lot of people affected," she said. "Not just the people that might be affected by any sort of border security."

"Everybody's going to have to compromise a little bit," Burr added.

Read more: 'We don't know when his next check will come': Federal employees are sharing how the government shutdown over Christmas is affecting their families

Like Burr, Bonita Williams was out of a job in Washington, DC, Monday. Williams, a grandmother who works as a janitor at the State Department, is employed by a government contractor. Her supervisor told her not to show up to work this week because of the shutdown.

"I don't know how I'm gonna pay my rent, because I work four hours a day, and if I miss one hour from work then my rent is short, 'cause I make just enough money to pay my rent and that's it," she told INSIDER.

This isn't the first time Williams has been unable to work because of a government shutdown. Earlier this year, during the first government shutdown of 2018, Williams said she was not paid for two weeks. She said she has been unable to find a full-time job since her hours as a janitor at the State Department were reduced from eight hours a day to four earlier this year.

"So, I'm just like, stuck between a rock and a hard place because I just have to keep trying to do the best I can with the part-time job that I had and now that got threatened by Trump, so then I don't know what I'm gonna do," she said.

Williams said the president keeps saying Americans agree with him about shutting down the government in order to secure funding for the border wall, but he actually doesn't understand the trouble some workers face now that they won't be getting a paycheck thanks to the shutdown.

"He never talked to me or my coworkers, you don't know what we're going through," she said. "Now our rent's not going to be paid."