The city could save millions of dollars under a new ruling, which found that special-education students who never try public school are ineligible for reimbursement for private-school expenses.

The decision by Judge George Daniels of federal District Court in Manhattan found that the family of a boy identified as Gilbert F. didn’t have the right to be reimbursed for tuition because Gilbert had never attended public school. He began attending a private special-education program in kindergarten at the Stephen Gaynor School on the Upper West Side.

Judge Daniels’s ruling overturned a 2000 decision by the city’s impartial hearing officer and another decision by the state Education Department’s state review officer.

It could send shockwaves through the growing community of parents who have never sent their children to public school but petition the city each year to pay for all or part of the youngsters’ tuition at private school.

In the last school year, the city Department of Education spent more than $12 million reimbursing the families of about 1,000 special-education students who had never attended public school despite the department’s recommendations. The number of families applying for reimbursement has more than tripled since the 1997-98 school year.

Yesterday, department officials said they were pleased with the decision. “We believe this is a sound decision and are pleased that the court agreed with our view,” the department’s general counsel, Michael Best, said.

The lawyer who represented Gilbert and his father, Neal H. Rosenberg, called the decision “very bad.”

“I don’t understand why the board is applauding itself here,” Mr. Rosenberg said last night in a telephone interview. “It’s almost like they are thrilled that a judge says they’re not obligated to provide services that they themselves recommend.”

He said his client and the city agreed that Gilbert needed special-education services. The question was whether the special services would be provided by the public-school system or by a private school. The city paid part of Gilbert’s tuition for the first two years of his schooling. In the third year the city refused to settle with the family, which led to a hearing and then more than four years of litigation.

Mr. Rosenberg said if Judge Daniels’s decision is upheld, some special-education students who try the public schools might be successful, but others will fail.

“It is asking a lot of parents to make a guinea pig of their child,” he said. “The risk society runs here is that the year will be so unsuccessful as to require two years or three years to make up for the bad year.”

Other lawyers who represent special education students whose families sue for reimbursement had similar opinions.

“It’s going to be a disaster for parents who don’t want to put their children in peril and in harm,” one attorney, Regina Skyer, said. She said parents shouldn’t have to put their children into public schools and watch them fail before being able to put them into private schools.

Another lawyer, Phyllis Saxe, who entered the field after her experience convincing the city to pay for the private education of a daughter with cerebral palsy, said she is “devastated” by the decision.

“I feel extremely bad for the special education children,” she said. “It’s a terrible emotional blow to hear that not only is your child disabled but that there is no recourse.”

She said if parents start trying out public-school programs and then pulling out their children to place them in private schools, “you’re going to have a lot of children who are going to be disturbed in addition to being disabled.”

The executive director of Advocates for Children, Jill Chaifetz, said most of her clients are poor and can’t afford private lawyers, and thus will not be affected by the ruling. But she said in many cases there aren’t appropriate placements for special-education students in public schools.

“The real issue here is to get more appropriate programs for kids with disabilities in the school system so they don’t need to make use of the private schools,” she said.

The chairwoman of the City Council’s Committee on Education, Eva Moskowitz, said although she doesn’t think parents should be granted a “free pass” for private school if the public schools can meet their child’s needs, there’s a shortage of good special-education programs in the public system.

“This ruling will result in students being forced to try a public-school program even if the public-school system offers no appropriate program,” the Manhattan Democrat said.

Mr. Rosenberg said he would advise the boy’s father, identified as Tom F., to appeal.