NEW YORK (PIX11) — Gov. Kathy Hochul signed a bill on Thursday putting a cap on the number of students allowed in New York City classes.

The bill would allow for no more than 20 students in classes form kindergarten through third grade, no more than 23 students in classes from fourth through eighth grade and no more than 25 students in classes from ninth through 12th grade. The change will be phased in over five years with a focus on schools in higher-poverty neighborhoods. Implementation will be delayed for a year.

“This bill reflects the need to ensure students have dedicated teachers devoting time and attention to their learning in person as we continue to come back from the COVID-19 pandemic,” Hochul wrote when she signed the bill.

The news was applauded by UFT President Michael Mulgrew, who represents teachers in New York City. He said they’ve been fighting for this for decades.

“We now have something to celebrate,” he said. “Governor Hochul has signed the Legislature’s bill that lowers class sizes across New York City, eventually bringing them much closer to the smaller classes that already exist in the rest of New York State.”

Mayor Eric Adams and Department of Education head David Banks have opposed the plan. They’ve said cutting class sizes will force the DOE to cut the budget elsewhere.

When the bill was being debated, education officials in New York City warned it would cost $500 million a year for kindergarten through fifth grade classes alone. There could also be billions in capital costs for building additional schools and classroom seats.

State Sen. John Liu, who backed the bill, said city officials “must stop with nonsensical rhetoric claiming ‘unfunded mandate’ and just get stuff done.”

Currently, many K-8 classes in New York City have an average number of 20-25 students, according to DOE data. Most general education classes at city high schools have an average of 21-29 students.

PIX11 has reached out to Mayor Adams’ office and the DOE for comment.