But they wouldn't all immediately lose their status. Instead, the process of expirations will continue for more than two years if Congress fails to act within six months, as President Trump has demanded.
Trump announced that his administration would grant no new applications for DACA if they were received after September 5 and would let existing two-year permits expire. But the administration is also allowing anyone whose permits expire in the next six months a brief window to renew, a move designed to give Congress time to act before any DACA status is actually lost.
So what would a DACA phase-out look like for the hundreds of thousands of people enrolled if lawmakers don't meet their deadline?
As many as 983 undocumented people previously covered under DACA would lose their protected status every day -- nearly 30,000 people a month, on average, for the two years following the six-month delay in the termination of the program, according to a CNN analysis of Department of Homeland Security data.
Here's a look at how recipients of the program are likely to lose to their participation in the program, according to new numbers from the Department of Homeland Security.
About 690,000 young adults are currently protected under the DACA program and more than 34,000 have already submitted their first-time applications to be processed.
During the six-month delay period, about 154,000 individuals' statuses are slated to expire; they have only until October 5 to renew their applications for another two years. Only 308 of the remaining protectees have already filed renewals, and their renewals will be the only ones considered for people with expirations beyond March 5.
Trump's move to end the 5-year-old Obama administration program comes after 10 states threatened legal action that could jeopardize the program. While Trump campaigned on immediately ending what he called an "amnesty," his administration continued to issue new permits as he spoke of his sympathy for the population covered under the program.
White House press secretary Sarah Huckabee Sanders said Trump "wrestled" with the decision, and the six-month window was designed to spur Congress to make the program permanent after years of Republican complaints that it was created only under executive authority.
Congressional leaders on both sides of the aisle have joined the call for legislation protecting the DACA recipients, who were brought to the United States as children and many of whom have grown up here and have never known another home than the US.
"Congress, get ready to do your job," Trump tweeted just hours before the decision was unveiled.