Living up to their fiercely insular reputation, 15 Brooklyn yeshivas have refused to let Department of Education personnel probe their inner workings for two years, according to a new DOE report.

The holdouts were part of a group of 39 Jewish schools being vetted for a lack of basic secular education in favor of immersive religious teaching.

In a letter to state education officials, schools chief Richard Carranza, who assumed his post well after the probe’s inception, signaled his disapproval of the blockade.

“The long delay in scheduling visits to this group of 15 schools is a serious concern,” he wrote, adding that he wanted guidance from state officials in dealing with the rogue schools.

Prompted by swelling complaints over minimal to non-existent instruction in basic academics, the DOE launched its probe in 2015. Critics have long questioned the pace and transparency of the investigation.

A group of 52 parents, alumni and other concerned parties named the 39 schools as exemplars of a system that they claim produces thousands of woefully undereducated young men each year.

The group said many yeshiva students receive no secular education at all after the age of 13, when they become fully engaged with religious study.

Sector supporters have long countered that pious parents have the constitutional right to emphasize religious study for their children and that the course of study differs from secular academics but is no less essential or educational.

In addition to the 15 resisters, another nine of the schools were excluded from the DOE’s report either because they were now defunct or were exempt post-secondary institutions.

The report said yeshiva representatives vowed to introduce revamped secular curricula into their schools that would tailor subject matter to Jewish beliefs.

“The schools have clearly made progress by creating culturally appropriate secular criteria and enlisting the supports necessary to implement them, including qualified external trainers, as described above,” the report states.

Carranza’s letter to state officials solicits their counsel in continuing to monitor yeshiva behavior and lauded those schools that showed authentic interest in expanding their offerings.

“I am gratified that some of the schools in this letter are committed to that path,” he wrote.

But longtime yeshiva critics weren’t satisfied by the report and said the study had been controlled by the subjects of the inquiry instead of the other way around.

“There was a lot of stalling that allowed for changes on the ground,” said Naftuli Moster, a vocal proponent of yeshiva reform. “I get the sense that this was yeshiva-led and not DOE-led.”

Moster noted that Carranza’s arrival came long after the probe began and he lauded him for finally getting the report out.

“I commend Chancellor Carranza because he came in only a few months ago and is reporting on the limited information he has,” Moster said. “For the time being, I’m not putting this on Carranza.”