Chicago Public Schools has been giving special priority for free, all-day Montessori preschool to families living in its wealthiest attendance area — a loophole that let in just four kids from outside that boundary in the last five years, the schools inspector general has found.

Inspector General Nicholas Schuler said that CPS should immediately halt the “unjustifiable” perk at Oscar Mayer Magnet elementary school, 2250 N. Clifton, that would be worth about $30,000 on average in similar private programs.

“Without any Board action, Mayer’s socioeconomic and racial diversity will almost certainly continue to move in exactly the opposite direction from that promoted in CPS’s magnet admissions policy, even though Mayer is a ‘magnet’ school and receives funding for extra positions as such,” Schuler wrote in a report released Wednesday. “Hundreds of parents residing outside Mayer’s boundary who would like their children to attend Mayer’s free Montessori pre-K are battling an annual admissions process that is stacked against them.”

Chicago Public Schools Inspector General Nicholas Schuler. | Sun-Times files

Chicago Public Schools Inspector General Nicholas Schuler. | Sun-Times files

Last year, Mayer accounted for nearly half of the 136 available free, full-day Montessori preschool spots in CPS, analysis by the IG’s data unit shows, and its staff salaries and benefits cost taxpayers $700,000.

Its student body is a CPS racial and economic outlier. Seven of every 10 Mayer students now are white in a district where white kids account for just one in 10, and its black population has fallen from 52 percent to 8 percent in 2008. The median income of its attendance area was measured this year at $177,947.25, CPS’ highest, Schuler said.

But schools officials stopped short of committing to end the unique admissions situation, agreeing instead to complete a 10-year demographic study of Mayer’s student body by Aug. 1 that it was supposed to conduct annually for the last decade. Then the school board will consider action they could vote on in February, right after the mayoral election.

“They are taking our recommendations seriously,” Schuler said. “But from our point of view, this seems to be an easy call. There just can’t be priority, free, full-day two-year Montessori pre-K for the most affluent boundary school in the city.”

CPS spokeswoman Emily Bolton declined to make any officials available for an interview. “We hope to have a process identified by Fall of 2018,” she said.

Mayer is one of just three schools in the entire city offering a full day of preschool for 3-year-olds regardless of need, and one of just four for 4-year-olds. Unlike those other schools that admit children using a citywide lottery, Mayer gave dibs on its 64 available pre-K places this school year to children living in its Lincoln Park boundary, and to its students’ younger siblings, leaving 686 3-year-olds on a waiting list.

That’s because unlike other magnets, which admit children from all over the city, the school never dropped its attendance boundary in 2008 as part of a compromise struck with vocal members of the neighborhood afraid of losing an attendance lottery.

But that compromise also required an annual demographic study to make sure that the school would remain accessible to the many African-American families who already traveled to Mayer after CPS invested in the Montessori program for grades pre-K through five and International Baccalaureate coursework for sixth- through eighth-graders.

Rufus Williams, Chicago’s school board president then, warned that the investments would push those students out as the magnet program succeeded in attracting white neighborhood families, who then made up 16 percent of the school. Though Mayer had plenty of space then to grow, Williams wanted a written commitment to diversity in the future. Officials wrote in requirements for the demographic study, language Williams recently told Schuler’s office was “purposefully obfuscatory.”