The Trump administration's phaseout of a program that spares young undocumented immigrants from deportation puts nearly 800,000 DREAMers on edge and their future on the clock.

An unwinding of DACA, the Deferred Action for Childhood Arrivals program, announced Tuesday by Attorney General Jeff Sessions, allows some to keep their deportation protections for up to two more years. But without congressional action to give them permanent protection, those enrolled in the program must begin making decisions now about their jobs, schooling, military careers and future country of residence.

Those affected were brought illegally to the United States as children. Now, at an average of 25, many know no other country than the U.S.

Ignacia Rodriguez of the National Immigration Law Center in Los Angeles, which advocates for immigrants, said it's difficult for native Americans to understand how drastic the move approved by President Trump is.

"They have to look at every aspect of their lives and figure out, 'How does not having DACA affect this?'" Rodriguez said. "It's quite scary and overwhelming."

Here's a look at what they're facing.

JOBS

A survey conducted by a University of California professor found that 91% of all DACA enrollees are currently employed. That figure rises to 93% for those who are over 25.

What happens once they lose their DACA status and work permit? Ian Macdonald, an immigration attorney with Greenberg Traurig, said even the most sympathetic business owners who boast about hiring DACA enrollees will have no choice but to lay them off if their work permits expire.

"Termination is going to happen with immediate effect," Macdonald said.

Do they try to hide the fact that their work permits are expiring in hopes of staying in their job? Do they tell their employer and hope for the best?

"We're going to be forcing a lot of these individuals back into the shadows and working illegally," Macdonald said.

Critics of the DACA program say the opening of nearly 800,000 jobs will be a boon for native-born workers. Roy Beck, president of NumbersUSA, said Trump delivered a "wonderful Labor Day present" to unemployed Americans by ending DACA, opening up those jobs to younger Americans struggling to find employment.

Business leaders say the opposite is true. Heads of more than 500 companies, including Apple, Facebook, General Motors, Google, Levi Strauss and United Airlines, sent a letter to Trump arguing that DACA enrollees are "vital to the future of our companies and our economy." The group estimated the U.S. could lose up $460 billion if those work permits are pulled.

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SCHOOL

Many DACA enrollees will still be allowed to study in high school, colleges and universities, but losing their protective status will make getting an education more difficult to afford.

The Supreme Court has ruled that all undocumented immigrants must be allowed to attend public K-12 schools. And the vast majority of states allow undocumented immigrants to attend public colleges and universities.

Undocumented immigrants face tight restrictions in three states. Alabama and South Carolina forbid undocumented immigrants from enrolling in all state universities, while Georgia forbids them from enrolling in some state universities, according to the National Immigration Law Center.

The hardest part will be paying for school.

Terry Hartle, senior vice president of the American Council on Education, which represents nearly 1,800 college and university presidents and executives, said DACA enrollees are ineligible for federal financial aid. That leads many of them to work side jobs to pay for school — jobs that will go away once they lose their work permits.

Many schools and private foundations have stepped in to help in recent years. For example, the University of Miami has a program that covers tuition and room and board. But at Yale University, the school makes clear that students need work authorization to offset their tuition through work-study programs.

That's why Hartle says the loss of work permits will have the biggest impact on DREAMers' ability to stay in school.

"I think private colleges and universities that provide financial assistance to DACA recipients will probably continue to do that regardless of what happens to DACA," Hartle said.

MILITARY

Undocumented immigrants could qualify for DACA if they served in the military. But it's unclear whether they will be able to continue doing so once DACA is rescinded.

The Pentagon adopted a policy in 2014 to allow undocumented immigrants with highly specialized skills to join the military. That includes people with rare foreign language expertise or specialized health care training.

The Department of Homeland Security did not say Tuesday what would happen to DACA enrollees currently in the military. The Defense Department did not respond to questions about the number enlisted or what would happen if their protective status expires.

DEPORTATIONS

The most pressing concern will be whether these DREAMers get to stay in the country.

Homeland Security said it will not target former DACA enrollees without a criminal record. But the department has been arresting more undocumented immigrants who have not committed crimes.

In January, the last full month of President Barack Obama's term in office, about 18% of undocumented immigrants arrested by Immigration and Customs Enforcement (ICE) agents had no criminal record. That percentage has increased each month of the Trump presidency, reaching 30% in June.

That means DACA enrollees will face a higher likelihood of being arrested and deported to their birth countries once their protections expire.