The new “unfunded” state-mandated smaller class size rule is projected to cost New York City nearly $2 billion annually once the change is fully implemented in five years.
The city’s Independent Budget Office released a new analysis of the controversial smaller class size rule slated to start this September, which Mayor Eric Adams repeatedly said would worsen the city’s predicted financial headache already compounded by its multi-billion dollar migrant crisis over the next several years.
The study concludes that the Big Apple’s Department of Education would have to hire at least 17,700 additional teachers to staff the new classes added — an estimated cost ranging from a low of $1.6 billion that could jump to a high of $1.9 billion (between the school years spanning 2025 through 2028), thanks to the 3% teacher raises negotiated this year by City Hall and the powerful United Federation of Teachers in their newly ratified union contract.
The law, signed by Gov. Kathy Hochul in 2022, places a 20-student max cap on kindergarten through third-grade classes; 23 for fourth through eighth grade and 25 for those in high school.


Opponents of the law have argued the hard numbers: Roughly 120,000 students and families have left city schools over the past five years, according to data provided to The Post in May 2022.
The drop in enrollment means schools with fewer students will receive less funding — complicating the question of where the money to support smaller class sizes will come from.
According to advocacy group Class Size Matters, kindergarten through third-grade classes averaged around 21.2 students in the 21-2022 school year compared to 23.8 students pre-COVID. For grades four through eight: 23.8 kids in 2021-22 fell from 26.5 in 2019-20; and 24.7 in high school from 26.4 students.

The DOE already has licensed teacher shortages in middle- and high-school English, math, sciences and Spanish, as well as bilingual and special-ed.
To meet the requirements of the law, the city must ensure 20% of classes meet the caps by the 2023-2024 school year and continuously increase the percentage to meet 100% by 2027-2028.
Schools Chancellor David Banks has created a 48-member “Class Size Working Group” made up of teachers, administrators, parents and education advocates to recommend how New York City public schools should plan to adjust to the new rules.

Banks previously said that the law has good intentions, but will be a burden on the already strapped schools budget.
“As a chancellor, I don’t fight against smaller class sizes — the issue for us has always just been about how you actually pay for it,” he said at a September town hall.
A DOE spokesperson slammed the law as an “unfunded” burden on the city’s coffers on Wednesday.
“The IBO’s independent report backs up what Chancellor Banks has been saying since this law was proposed – while we support lowering class sizes, this unfunded law will require very real, serious tradeoffs and hard choices,” the rep Nathaniel Styer told The Post.
“The report also highlights a number of the challenging implementation decisions ahead of us beyond costs, such as whether to reduce enrollment at our highest-demand schools and how to weigh investments in reducing class size against priorities like additional course offerings and enrichment programs.”