The struggling schools in New York City’s “Renewal” improvement program serve nearly 6,300 fewer students today than when the program started, a sign that many families are still shunning the schools even as the city spends hundreds of millions to revamp them.

Eighty-one of the 94 schools in the program — or 86 percent — enroll fewer students now than they did when the program launched in fall 2014, according to a Chalkbeat analysis. The schools with high school grades lost an average of 146 students each, with many shedding far more: DeWitt Clinton High School in the Bronx serves nearly 600 fewer students today than it did in 2014.

Enrollment had been dwindling at most of the schools in the Renewal program well before it began. But the hugely expensive program — which is projected to cost nearly $839 million over five years — has so far failed to stem the exodus of students. In fact, the year-over-year enrollment drop at those schools was larger after the Renewal program started than in the two prior years.

The schools’ overall enrollment fell from about 45,140 students in 2014 to roughly 38,870 today, according to the analysis. They are losing students in a variety of ways: Some are dropping out, others are transferring, and fewer students who arrive mid-year are being sent to those schools. At the same time, many are enrolling fewer students as demand for their seats diminishes.

“You have 94 schools you’ve sort of said are your loser schools,” said Kim Nauer, education research director at the New School’s Center for New York City Affairs. “We have a system with a lot of choices, and the ‘Renewal school’ label is not helping them.”

Recently, the city has taken steps to boost enrollment at the schools, including by allowing more students to apply to them. As a result, officials said they project a 13 percent increase in incoming sixth-graders at Renewal middle schools this fall.

However, Renewal high schools are expected to enroll 7 percent fewer ninth-graders this September. That suggests that the city’s enormous investment in the schools has not yet rehabilitated their reputation among families and students, who are able to apply to any of the city’s roughly 400 high schools.

Sagging enrollment is an existential threat for New York City schools, since their budgets and staff levels are determined largely by the number of students they serve. When school populations shrink past a certain point, the city must inject them with extra funding just to maintain basic courses like math and English, to say nothing of art classes and extracurricular programs.

This academic year, Chancellor Carmen Fariña announced plans to consolidate seven Renewal schools and shut down three others mainly because they had grown so small.

“Schools with such a low enrollment cannot provide the robust education our students deserve,” she said in December.

In the past, de Blasio administration officials have indicated that the threshold for being able to provide a full range of classes and services is 250 students. There are now 23 Renewal schools serving fewer than 250 students, excluding the 10 schools already slated to be closed or combined.

Brooklyn Generation School in Canarsie has shrunk by 65 students since 2014, despite a higher graduation rate and a suite of new arts classes and counseling funded by the Renewal program. Assistant Principal Louis Garcia said the school has coped with the funding loss by slashing expenses.

“We just don’t buy paper,” he said. “We’re trying to keep everybody on staff.”

The enrollment dip at Brooklyn Generation is dwarfed by that at other Renewal high schools.

Since 2014, Herbert Lehman High School in the Bronx has shed 577 students, John Adams High School in Queens has lost 394 students, and Flushing High School, also in Queens, shrank by 381 students. The population of Brooklyn’s Boys and Girls High School plummeted from 648 to 343 students — a 47 percent enrollment drop from one school year to the next.

Overall, the 35 Renewal schools with high school grades are down 4,900 students since 2014.

The enrollment at many Renewal elementary schools also fell, even though they are assigned students who live near them. For instance, P.S. 132 in Manhattan serves 90 fewer students now than it did in 2014, while P.S. 165 in Brooklyn is down 52 students. The declines could be caused by families opting for charter schools or taking advantage of a federal law that lets them transfer out of the lowest-performing schools.

Part of the overall decline was due to the city intentionally sending some of the Renewal schools fewer students who enter the system after the official admissions process, since those students can pose extra challenges. In addition, some high schools have trimmed their own rosters by referring some of their most struggling students to “transfer” high schools, which are designed to catch up students who are behind in credits.

Still, paltry demand for seats at the Renewal schools appears to be a major enrollment challenge. Staffers at a few schools said the city had done little to help them pull in new applicants.

“They give generic advice about marketing yourself,” said an administrator at a Renewal high school. “It’s just on us to attract students.”

City officials are hoping that their recent efforts will slow the schools’ enrollment slide for the coming year.

Education department spokesman Will Mantell said the city provided four training sessions this fall where Renewal middle and high school leaders learned recruitment strategies, including how to showcase their schools at application fairs and how to use data to target their outreach efforts. Department employees also made house calls last year to tell families about the new services offered at Renewal schools.

And in the latest admissions round, the department opened the Renewal middle schools to any fifth-graders in their boroughs — not just their districts, as is the case for many middle schools. After that change, the schools received about 5,000 additional applications this year, Mantell said.