It's because their families owe money and the school board is cracking down.
"For many, its the only hot meal they will get," Dr. Robert Holster, Passaic's Superintendent, said.
School officials want the kids to eat, but families who are required to pay and don't have left the district with tens of thousands of dollars in unpaid lunch fees.
"For years I ignored it. I let them eat. I know the board feels bad, but had to take a stand," Holster said.
The board passed a new rule in September. Any student required to pay and who exceeds a 50 dollar tab can't get lunch.
It's hard to stomach for parents and students.
"That's terrible. Kids need to eat," parent Juan Perez said.
"It's bad. If they don't eat, they don't have the energy during the day," student Lamont Stalling said.
It's a district where most families struggle to make ends meet. Ninety-two percent get free or reduced lunch. The district has not be able to collect more than 23-thousand dollars due this year. Last year, the amount hit more than 130-thousand.
They hope this "no lunch" stand will prompt more families to sign up for free lunch that the federal government pays for, but Dr. Holster says that poses it own hurdles in a largely immigrant community.
"When you raise questions about identity, you raise fear about giving too much information," he said.