More than 336,000 people in England were waiting for an autism assessment in September, according to new NHS figures, with nearly nine in ten having waited longer than the three months recommended by national health guidelines.
NHS England data published on 12 November put the number of people with an open referral for suspected autism at 336,764 at the end of September 2026. That is 34% higher than a year earlier and 2.7% higher than the 327,871 waiting at the end of August.
Of those waiting, 292,180 — 86.8% — had been referred at least 13 weeks earlier. The National Institute for Health and Care Excellence (NICE) recommends that a diagnostic assessment should begin within three months of referral. In some parts of England, average waits stretch to three years and seven months, according to the National Autistic Society.
The charity, which highlighted the figures, said the rising number of diagnoses did not mean autism itself was becoming more common. Instead, it said, better understanding and improved recognition were bringing forward people who had previously been missed, particularly women and girls. A diagnosis, it added, could be life-changing, unlocking understanding, education, employment and support.
But the charity warned that long waits were pushing many people into crisis. It said successive governments had failed to match assessment capacity to demand, and that the national autism strategy published in 2021, which promised to cut waiting times, had effectively been abandoned since 2022, with the deadline for a refreshed strategy already missed.
The National Autistic Society also said there was no NHS workforce plan for autism assessments, that autism was not mentioned in the NHS 10-year plan, and that spending by local health boards on private providers to carry out assessments had more than doubled in the last year because of a lack of internal capacity.
“An autism diagnosis can be life-changing,” said Joey Nettleton Burrows, the charity’s policy and public affairs manager. “But long wait times mean that autistic people are faced with avoidable delays, pushing many into crisis, with no consequences for the Government or NHS England when wait time targets are repeatedly missed.”
The charity is calling on the new prime minister to write and fund a new autism strategy, provide enough funding for assessment capacity, and build a system that supports people both before and after an assessment. It also warned against any move to a needs-led system that abandons those already waiting, saying it would only increase harm.
The figures cover England only and are published as experimental statistics by NHS England.
Sources: NHS England Digital, “Autism Statistics, October 2025 to September 2026” (https://digital.nhs.uk/data-and-information/publications/statistical/autism-statistics/october-2025-to-september-2026); National Autistic Society, “Autism assessment waiting times” (https://www.autism.org.uk/what-we-do/news/autism-assessment-waiting-times-november-2026).
