The nation’s largest school district is being accused of failing to provide speech therapy, occupational therapy and other legally-mandated services to students with disabilities.

A federal lawsuit filed late last week against the New York City Department of Education alleges that the school district routinely leaves students without therapies they are entitled to under the Individuals with Disabilities Education Act.

The suit filed on behalf of Bronx Independent Living Services and two affected children seeks class-action status.

When the district is unable to find providers for therapy and other related services, it issues a voucher known as a related service authorization so that parents can obtain those services from a private provider.

However, the complaint alleges that the approach is severely flawed, with few providers willing to accept the vouchers and parents left to coordinate services that are supposed to take place at school.

“The DOE must stop pretending it is meeting its legal obligations by transferring its duties to parents who are often overburdened,” said Michelle Caiola, director of litigation at Disability Rights Advocates, a nonprofit that filed the suit. “The law requires the services actually be provided, but DOE’s own data show that is not happening.”

A report released last month by New York’s Public Advocate Letitia James found that in some areas of the city as many as 91 percent of the vouchers go unused.

Hardly any of the providers on lists given to parents were actually willing to accept the vouchers, James found. And, her report showed that parents often face barriers in getting their kids to therapists with few of the providers willing to come to them.

“Such a heavy reliance on related service authorizations has made it increasingly difficult for students and parents to obtain their legally mandated services and is leading to the gross neglect of students with disabilities,” James said.

The lawsuit cites the experience of a 9-year-old with autism who missed out on occupational therapy during “critical development years” when he could have gained motor skills like learning to hold a pen.

Meanwhile, a 12-year-old with Down syndrome was unable to access therapy because his mom lacked transportation and child care so that she could take him to after-school sessions, according to the suit.

The complaint calls for immediate changes in the way New York City offers related services to students with disabilities including measures to track children to make sure they’re receiving what they’re entitled.

“We are dedicated to meeting the needs of students with disabilities and in the small percentage of cases when we issue a related service authorization, we work with families to connect them with an appropriate provider in their area,” a spokeswoman for the city’s Education Department told The New York Times.