The Hawaii Disability Rights Center filed a class-action lawsuit yesterday seeking to extend special-education services in public schools for students until they turn 22.

The cutoff is now 20.

"The concern is that disabled students in Hawaii are being deprived of an education after age 20," said John Dellera, executive director of the center. "Throughout most of the country, disabled students have the right to an education … until they’re 21 or 22."

The state Department of Education declined comment because officials had not yet reviewed the lawsuit.

Dellera said the class action is about providing equitable educational opportunities to special-education students.

General-education students who do not complete high school programs can enroll in adult education, he said, but that option is not open to special-education students seeking vocational or independent-living training.

He also pointed out that only Hawaii and Maine set the cutoff for special education at 20 years old.

Most other states set it at 21 or 22 years old.

The lawsuit, filed in U.S. District Court, seeks to stop the state from enforcing a law passed in the last legislative session that formally puts the age limit for students in public school at 20.

The law was passed following a federal court ruling in 2009, on a suit filed by the center, which said special-education students were being moved out of schools at 20 — the state’s age limit for public schools set in the 1960s — but that general- education students were being given special permission by principals to stay longer (as allowed under the old law).

"The court ordered Hawaii to treat everybody equally," Dellera said.

The federal government says states should provide a free education to disabled students until they turn 22, unless the state lowers the maximum age for all students.

Four students joined the center in the class-action suit.

Dellera estimates that hundreds of special-education students each year could gain from the extra years of education.