A federal appeals court said the state failed to provide a special needs student with an appropriate public education.
The autistic student was enrolled in Horizons School, a private special education facility on Maui, at the state's expense.
In 2010, state education officials held the student's annual program review without his father present then changed the program and enrolled the student at Maui High School.
The court said excluding the boy's father was wrong.
"The 9th Circuit decision made clear that the requirements were not met and parental participation is not a corner that can be cut and I think the 9th Circuit decision strengthens our ohana," said Robert Badger, the attorney for the student and parent.
The boy's family kept him enrolled at Horizons School at their own expense.
The appeals court sent the case back to federal court in Honolulu to determine if the family is entitled to tuition reimbursement by the state.
The DOE said it is reviewing the decision and intends to fully comply with the law.