About a quarter of the 94 Renewal schools improved enough to leave the program; another quarter have closed, removed grade levels or combined; and 50 remain. It is unclear what will happen to the schools that are still in Renewal.

Renewal was built on the theory that academic performance would improve if children were given a wide array of social services and teachers were better trained. The city paid for an extension of the school day, professional coaches for teachers and a suite of social supports such as mental health clinics, dentists and food pantries on site.

But in interviews with nine city staff members who worked on Renewal, all said it was clear within the first year that the program was veering off track. The staff members requested anonymity because they were still working with the city and were not authorized to speak or they did not want to jeopardize future employment.

Principals interviewed said confusing lines of authority meant they often did not know who their bosses were, which in turn left teachers puzzled. Department of Education officials suggested making academic goals easier to reach so more schools could be called a success, an internal memo showed. Staff members hesitated to close at least one school to avoid political backlash.

Mr. de Blasio declined to be interviewed for this article. His spokesman, Mr. Phillips, defended the program.

“The Renewal school program wasn’t a silver bullet,” Mr. Phillips said. “But it sure made a big difference in the lives of kids and parents at improved schools that would have been closed by prior administrations. The mayor views the program as a foundation, not the endgame.”

In a radio interview on Friday, conducted after this article was published, Mr. de Blasio defended the concept behind Renewal and argued that Mr. Bloomberg’s policy of closing schools was often harmful.