For some people, the checks will stop coming on Tuesday. For others, the deadline is later in the month.
In Philadelphia, that would mean some 18,000 families would lose their unemployment benefits next month.
By April, 300,000 people in Pennsylvania would be affected.
People in New Jersey would not be immediately impacted but, in Delaware, as many as 1,000 people could lose their benefits this week.
One of the people who would be affected is Caroline Trueheart of Southwest Philadelphia. She was laid off a year ago and since then, like many people, she has been living off of $300 per week in jobless benefits.
"My lights are getting ready to go out, my heat," Trueheart said. "I don't know what I'm going to do."
Here's what's happening: Traditional state jobless benefits run up to 26 weeks. After that, you could get unemployment checks through two separate programs.
A permanent program called Extended Benefits provided up to 20 weeks of benefits. A temporary program called Emergency Unemployment Compensation or EUC provided an additional 53 weeks.
It is these programs that will cease to exist in most states.
"So it's going to be a rolling numbers of people, of thousands of thousand of people losing their income," said John Dodds of the Philadelphia Unemployment Project.
People who've run out of benefits can try to turn to other sources of support, like food stamps.
But the number of food stamp recipients is already at a record high of 42.4 million.
"There's not a whole lot out there - soup kitchens, food cupboards, things like that - but it's really going to be hard," said Trueheart.
Here's one way you can help families about to lose their benefits.
In an effort to help people who could lose their benefits, the Philadelphia Unemployment Project has organized a holiday toy collection for children of the unemployed.
Call 215-557-0822 or click on this link for drop-off locations.
On Wednesday the Philadelphia Unemployment Project is taking a busload of people to Washington, D.C. to call for the reinstatement of these benefits.
If you would like to join them, the bus is leaving at 7:00 a.m. from 16th and JFK.