And what that means for you — plus how private assessment can help

At AG&Co Health we specialise in private assessments for autism and ADHD — and one of the questions we hear most often is: “How long will I have to wait on the NHS for an autism assessment?” It’s an understandable concern, so in this post I’ll walk you through the latest data on wait times for the National Health Service (NHS), what influences the variation, and how to make sense of it — especially if you’re considering a private assessment.

What the data says:

Here’s a summary of what the numbers show:

• According to the National Autistic Society (NAS), as of December 2024 there were 224,382 people in England waiting for an autism assessment. Note that around 90% of those waiting had already waited longer than the guideline time of 13 weeks.

The average waiting time is now “over 14 months” for many people...

So, in short — yes, the waiting list is very long and many people are waiting well beyond what the guidelines recommend.

Why the wait times are so long:

There are several reasons why the wait list has grown and why waits vary so much:

• Increased awareness & referrals: More people are aware of autism, more adults are seeking assessments, and that means higher demand on services.
• Resource constraints: Specialist diagnostic services need trained staff, time, and funding. Many services are stretched.
• Geographical variation: Wait times differ depending on your local NHS trust / area. Some regions might have longer waits due to fewer resources or higher demand.
• Backlogs from the pandemic: The service disruption caused by COVID-19 means many assessments were delayed or postponed, and services are still catching up.
• Complexity of cases: Autism assessments, especially for adults or when co-occurring conditions exist, can take more time to schedule and complete.

All of this means that while the guideline is 13 weeks, the reality is often many months, and in some cases years.

What that means for you:

If you or someone you care about has been referred for an autism assessment via the NHS, here are a few practical points to keep in mind:

• Be aware of your referral status: Check with your GP or the referral service which stage you’re at — have you been placed on the waiting list, are forms required, is there a screening questionnaire?
• Support isn’t off-limits while you wait: Even before the formal diagnosis, support can often be arranged (via GP, local support groups, schools etc)
• Be realistic about the timescale: Unfortunately, you should prepare for many months wait — and possibly over a year, depending on your area.
• Consider regionally how long the wait is: If you know your NHS trust area, you might check whether they publish average waiting times (some trusts do).
• Stay proactive: Keep in touch with the service, complete any required forms promptly, chase as necessary — all of these can help ensure you don’t drop off the radar.

Why we offer a private pathway:

As a private provider specialising in autism and ADHD assessments, we often see how the long NHS waits affect people’s lives: delayed access to support, continued uncertainty, longer periods without clarity. At AG&Co Health we aim to offer:

Quicker access: While private assessments aren’t guaranteed faster in all cases, they can often reduce the wait significantly.

• Focused diagnostic support: A dedicated assessment pathway means you can often get through the various stages (forms, screening, interview, feedback) in a streamlined way.
  
• Clarity & control: You have more choice of provider, more say over timing, and often more flexibility in how the assessment is arranged.
  
• Support beyond diagnosis: A diagnosis is a key step — then comes understanding support needs, next steps, planning — we aim to help with that.
  

Of course, private assessment isn’t appropriate or affordable for everyone — and the NHS remains a vital route. But knowing what the NHS wait looks like and considering all your options can empower you to make the best decision for your situation.

Final thoughts:

In summary: yes, the NHS wait list for autism assessments is long, and many people are waiting well beyond what the guideline of 13 weeks would suggest. The average is now over a year in many parts of England. That doesn’t mean there’s no hope, knowing the landscape, being proactive, exploring options (including private) can make a difference.

At AG&Co Health we’re here to support you through that journey: from referral or suspicion through to assessment, diagnosis, and planning what comes next. If you’d like to talk about how a private assessment could work for you just get in touch, we’re always happy to chat.