New York City spent $151.6 million in the 2016-17 school year on salary and fringe benefits for teachers in the Absent Teacher Reserve, according to numbers recently obtained by Chalkbeat from the city’s Independent Budget Office.

That’s higher than previous estimates on the cost of the ATR — a pool of teachers without permanent positions — which have generally hovered around $100 million. The high cost is no doubt one reason the city is eager to reduce the pool, which included 822 teachers at the end of the school year. Earlier this month, it announced plans to halve that number by placing hundreds into open vacancies in classrooms as of Oct. 15, potentially despite principal’s objections.

The IBO says its numbers come directly from school budgets prepared and provided by the city’s education department, in which ATR costs are included in their own separate lines. Officials in the city’s education department did not dispute the numbers but said they did not know exactly what methodology or point in time the IBO was capturing. “The number, salary, and overall cost of teachers in the ATR pool naturally fluctuates from day to day throughout the school year,” they said.

Teachers are placed into the ATR when their jobs are eliminated or for disciplinary reasons. As of October 2016, there were 1,304 teachers in the ATR pool, according to numbers released by the city last fall. Using the IBO’s estimate, on average each ATR teacher received a total of $116,258 in salary and fringe benefits for the past school year. (By comparison, the base salary for a city teacher as of May 2017 was $54,000). The IBO did not break down salary versus fringe benefits.

David Bloomfield, a professor of education at Brooklyn College and the CUNY Graduate Center, said he was not shocked to learn that the actual cost of the ATR pool was higher than previously estimated. “It doesn’t surprise me,” he said. “I think the administration has tried to lowball the figure to avoid criticism.”

He noted that the ATR is a problem inherited by Mayor Bill de Blasio from former Mayor Michael Bloomberg — and not an easy one to solve. Still, he added, if the city is already paying as much as $151.6 million, it should consider instead passing a buyout plan with higher incentives for teachers than the $50,000 in severance pay the city is currently offering.

Instead, the city plans to place these teachers in classroom vacancies, where the schools will have to grapple with their salaries instead. While the city provided subsidies to schools hiring from the ATR in the past, under the new policy schools would have to bear the full cost of the new hires.

According to Mark Cannizzaro, executive vice president of the city’s principals’ union, if an ATR hire causes a “budgetary restriction” for a principal, the city will work with principals to resolve the issue. He did not provide more details.

The city has vowed to work with schools to find the right fit. “We are reducing the size of the ATR pool with a number of common-sense reforms that drive resources back to schools and ensure qualified teachers are deployed effectively,” education department spokesman Will Mantell said. “These reforms will support the work our schools are doing every day, while also significantly lowering costs.”