Thousands of children in England with special educational needs are waiting too long for an education, health and care plan (EHC), the BBC has learned.
The EHC plans set out a child's needs and the support to which they are entitled.
Once a plan is requested, the law says councils should normally finalise them within 20 weeks.
But through Freedom of Information requests, the BBC has learned around four in 10 plans have taken longer.
The BBC asked 152 councils in England about the time it took to issue EHC plans.
Sixty-five councils provided comparable data for the last four academic years, starting in 2014-15.
Over that period, 26,505 applications took longer than 20 weeks to finalise - including more than 6,000 last year alone.
The longest wait for an individual application was in Suffolk - where it took the council 1,023 days, or nearly three years, to finalise one EHCP application.
Suffolk County Council said an increased demand for EHCPs had proved particularly challenging - happening at the same time as the transfer from the old system of Statements of Special Educational Needs (SEND).
Councillor Gordon Jones, the council's cabinet member for education and skills, said: "Our priority is to ensure every child gets the correct help and support they need to prosper and develop.
"The increase in demand for education, health and care needs assessments for children and young people in Suffolk is a matter that I am taking very seriously.
"The development of our SEND strategy is driving improvement across SEND and all agencies involved in Suffolk."
Fifty-two councils told us that they had taken more than a year to finalise an EHC plan for at least one child.
While thousands of families are still waiting longer than 20 weeks for a finalised plan, the data suggests the mean and median waiting times are improving at many councils.
The number of parents taking councils to tribunal to challenge them at various stages of the EHCP process nearly doubled over the four years - up from 1,041 in 2014/15, compared with 1,988 in 2017/18.
Fifty-eight councils provided comparable data on these appeals.
Nadhim Zahawi, Minister for Children and Families, said: "Our ambition for children with special educational needs and disabilities is exactly the same for every other child.
"We are pleased to see that local authorities are improving the speed at which they are assessing SEND children.
"Where a local authority is performing significantly below the national average, we have been working with them through our specialist team of SEN advisers to improve performance."