The city finally got specific about its plans to expand after-school programs for middle schoolers today.

A report released by the mayor’s office provides the first glimpse into how the city wants to spend $190 million more on after-school programs, and its per-student cost estimates indicate that the plan has undergone significant shifts over the last few months. Those figures are likely to take center stage when Mayor Bill de Blasio heads to Albany tomorrow to lobby lawmakers to allow a tax increase to pay for his ambitious education initiatives.

“This is not a small undertaking, it’s not a pilot project, it’s not a boutique effort for only a few schools,” de Blasio said today. “This is system-wide change.”

The total funding estimate for de Blasio’s plan to expand pre-kindergarten and the after-school programs has remained steady since he was on the campaign trail: $530 million per year, or what he estimated that a tax increase on the city’s highest earners would raise. 

But some aspects of the after-school plan have clearly been in flux since January, when the mayor’s press secretary told NY1 that the program’s estimated cost was $1,600 per student. Today’s plan estimated the cost of each new after-school seat at $3,000.

“At $3,000 per program slot, more programs will be allowed to hire certified teachers to serve as educational specialists and to retain more highly educated and experienced activity specialists – such as professional artists and graduate students in science – who can be paired with youth workers to offer engaging, project-based learning activities,” the report says.

While the mayor’s pre-K was spelled out in a lengthy implementation plan and a follow-up “progress report” last week, the after-school plan has so far been thin on those kinds of details. The pre-K initiative will be even more costly and requires overcoming larger logistical hurdles in school buildings across the city.

But what the after-school plan will require—in addition to $190 million—is input and resources from middle schools themselves, according to the report. Principals will be required to contribute to the programs at their school through “in-kind donations” of curriculum materials and potentially teachers’ time.

“Working together, principals and middle school teachers will help after-school staff, including education specialists, to align programming with school-day instruction and assist participants with their transitions from one grade to the next and to high school,” the report says.

De Blasio’s plan calls for every middle school in the city to offer the after-school programs, more than doubling the number of schools offering those programs. Charter schools with middle schools will be eligible for additional after-school programming if they don’t already have extended-day programs.

Programs will be required to operate for nine hours each week for 36 weeks of the school year, and 60 percent of students’ time must be spent in structured activities like dance, sports, literacy or science-related activities, or community service projects. (The unstructured time can also include recreation and homework help.) That structure and cost per student aligns with the city’s Middle School Quality Initiative extended day program.

One challenge the middle-school program shares with the pre-K expansion will be evening out the quality among programs. The city’s after-school programs already vary widely in their funding and their use of certified teachers and subject-area experts.

The report notes that many high-quality after-school programs currently do their own fundraising to supplement city funds, and the $3,000 price tag will pay for a more equitable system with more certified teachers.

On Monday, de Blasio said programs will be evaluated by academic measures like improvements in students’ homework completion, class grades, and test scores, as well as non-academic measures like school attendance and students’ engagement in the activities.

The report also quantified how many after-school seats are already being funded by the city: just over 45,000 in 239 schools. The city’s plan will bring that total number of seats to over 95,000, with the $190 million covering the increase, not the entire cost of the city’s after-school programs.

We’ve embedded the whole report below.

Patrick Wall contributed reporting.