The Ministry of Education has admitted it needs to do more to help children with behavioural and learning problems, saying the current waiting list for an early intervention service is "not acceptable."
More than 2,500 children under five are on waiting lists to get diagnoses and specialist support and parents are worried their children are being left behind.
In the past year nearly 14,500 children received an Early Intervention Service, which provides support for children who have developmental or learning delays, a disability or a behavioural difficulty.
The average wait list to see a specialist is 71 days but can be up to 300, depending on where you live.
The highest wait in the country is in Wellington where the average is 130 days.
The Ministry of Education says the number of children coming through the service is growing.
"We have to admit that we have a challenge around the wait list time for some kids and we are working really hard to address that because in our view that's not acceptable," Dr David Wales said from the Ministry of Education.
"The early years are vital and that's why we are wanting to pay attention to this wait list challenge, the longer some of these problems wait, the more difficult is is to resolve them."