Children with severe disabilities need more help preparing for life after school, special education advocate Mark Shanks says.
Mr Shanks spent a year interviewing 40 families with disabled children about their transition from school for charitable trust Life Unlimited, which supports disabled children and their families.
He said children with the most severe disabilities qualified for support from the Ongoing Resourcing Scheme (ORS) and tended to stay at school until they were 21.
Mr Shanks said the students were eligible for a one-year Ministry of Social Development transition programme that prepared them for life after school, but that was too little too late.
"If you're in your last year of school and you've stayed at school till you're 21, that means you're 20 years of age before you've got any constructive transition plan. It's too late, you cannot do it in that year," he said.
"You cannot get a good outcome for that young person in one year."
Mr Shanks said the Education Ministry recommended planning for the transition of disabled students from school start when children were aged 13 or 14, "but it's not followed".
"I'd like to see ERO evaluating special needs classes and learning support centres against those guidelines and, if they did, I think we'd start to see some change."
He said the current system made it hard to prepare disabled students for independent living. Support for disabled students preparing to leave school should be better co-ordinated.
"There's no clear pathway, there's no real plan in place and I think this is the biggest finding from my report - planning is talked about, but it's not done," he said.
Mr Shanks said parents kept disabled children at school as long as possible because they wanted to delay the shift into the adult world.
He said half of the 40 families he studied were considering placing their children in residential care after they finished school.
Mr Shanks said that was an expensive option for the government, and it would be better to prepare disabled children to live more independent lives.
Education Ministry head of learning support David Wales said there was not enough planning for the transition for some disabled students.
He said the special education system was changing to ensure each child had one person to plan and co-ordinate their support.
Mr Wales said nearly half of the ORS-funded students who stayed at school after the age of 20 achieved an NCEA qualification.
He said 23 percent got NCEA Level One and 18 percent got Level Two, so it was worth staying on.