Step-by-step guide · Updated June 2026
How to Get an Adult Autism Assessment in the UK
Getting an autism assessment as an adult in the UK is more achievable than many people realise. Whether you are exploring NHS Right to Choose, going private, or are in Scotland, Wales, or Northern Ireland — this guide walks you through every step.
This guide is for information only and does not constitute medical or clinical advice. Always consult a qualified healthcare professional about your individual situation.
Your options at a glance
NHS Right to Choose
England onlyNHS Standard Referral
All UKPrivate Assessment
All UKStep-by-step: from first question to diagnosis
Recognise the signs and seek information
Many autistic adults are diagnosed late — often in their 30s, 40s, or older — having spent years feeling different without understanding why. Common signs in adults include difficulty with social situations (though not all autistic people struggle socially), sensory sensitivities, strong preference for routine, intense focus on specific interests, difficulty with unwritten social rules, and exhaustion from "masking" — suppressing natural behaviours in social settings. Women and non-binary people often mask more effectively and are diagnosed later. Reading about autism from autistic voices (rather than only clinical sources) can help you recognise your own experience.
Understand the assessment routes available
In England, NHS Right to Choose allows you to ask your GP to refer you to any CQC-registered autism assessment provider at no cost. Wait times via Right to Choose are typically 12–26 weeks. Fully private assessment is available within 2–8 weeks at most providers and requires no GP referral. In Scotland, Wales, and Northern Ireland, NHS Right to Choose does not apply — referrals go through your local NHS Board or Health Board, with waits often exceeding two years. Private assessment is the main faster alternative in those nations.
Visit your GP
For NHS Right to Choose, your GP must issue a referral letter to the provider you choose. Your GP cannot legally refuse a Right to Choose referral to a CQC-registered provider. If your GP is unfamiliar with the policy or tries to decline, use our GP letter template and point them to NHS England's Right to Choose guidance. For a private assessment, most providers accept self-referral — no GP letter required. It is still worth telling your GP you are pursuing an assessment, so it is on your medical record.
Choose a provider
When choosing an autism assessment provider, key things to check: whether they use the ADOS-2 (gold-standard observational tool) and ADI-R or equivalent developmental interview; whether they are CQC-registered (England) or regulated by HIS/HIW/RQIA in other UK nations; their stated wait time and price; whether they have experience assessing adults specifically (some providers focus mainly on children); and whether they offer combined AuDHD assessment if you suspect you may also have ADHD.
Prepare for your assessment
An adult autism assessment typically spans 2–4 appointments. You will usually be asked to complete pre-assessment questionnaires about your history, sensory experiences, and social communication. You may be asked to provide childhood evidence — old school reports, letters from parents or siblings, or any other documentation that speaks to how you were as a child (assessors look for signs of autism from early childhood, even if you were not recognised as autistic at the time). If possible, have a trusted person who knew you as a child provide a brief written statement. The ADOS-2 session involves structured activities and conversation with the clinician — it is not a test with right or wrong answers.
Understand the ADOS-2 and ADI-R
The ADOS-2 is the gold-standard observational assessment for autism. The clinician conducts structured activities and conversations while observing specific social communication and interaction behaviours. It typically takes 45–90 minutes. The ADI-R (Autism Diagnostic Interview — Revised) is a structured interview covering developmental history, usually conducted with the person being assessed and sometimes with a parent, carer, or sibling. Together these give clinicians the best picture of whether the autism criteria are met. Not all providers use both — ask when enquiring.
Receive your diagnostic report
After your assessment, the clinician will issue a written diagnostic report — usually within 2–6 weeks. The report will confirm whether an autism diagnosis was reached and include recommendations. Even a "not meeting criteria" outcome can be useful — it will usually explain what was found and suggest alternatives. Keep several copies of your report, as you will need it for workplace adjustments, benefits applications, and to share with other healthcare professionals.
Frequently asked questions
Can adults be diagnosed with autism?
Yes. Autism can be diagnosed at any age. Many adults are diagnosed in their 30s, 40s, 50s, or later — particularly women and people who masked their autistic traits in childhood and school settings. A late diagnosis can be life-changing, providing context for a lifetime of experiences.
How much does an adult autism assessment cost in the UK?
Private adult autism assessments in the UK typically cost £1,495–£2,500, depending on the provider and the tools used. A combined AuDHD assessment (autism and ADHD together) usually costs £2,500–£3,500. Via NHS Right to Choose in England, there is no cost to the patient.
What is the difference between an autism assessment and an ADHD assessment?
Autism assessments use tools like the ADOS-2 and ADI-R to examine social communication, sensory processing, repetitive behaviours, and developmental history. ADHD assessments use tools like the DIVA-5 or Conners scales to assess attention, hyperactivity, and executive function. The two conditions frequently co-occur — around 50–70% of autistic adults also have ADHD — and many providers offer combined AuDHD assessments.
Do I need a GP referral for an adult autism assessment?
For NHS Right to Choose (England only), you need a GP referral letter to a CQC-registered provider. Your GP cannot refuse this. For a private assessment, most providers accept self-referral without a GP letter.
Will an adult autism diagnosis be accepted by employers and the NHS?
A diagnosis from a CQC-registered private provider carries the same clinical validity as an NHS diagnosis and is accepted by employers for reasonable adjustments under the Equality Act 2010. NHS GPs should record it on your medical history. Benefits agencies (DWP) accept private diagnoses for PIP and other applications.
What happens after an autism diagnosis as an adult?
An autism diagnosis entitles you to reasonable adjustments at work under the Equality Act 2010. It can support PIP and other benefit applications. It may explain past difficulties and open access to community support groups and specialist services. Medication is not part of autism treatment (unlike ADHD), but therapy — particularly CBT adapted for autism or Acceptance and Commitment Therapy (ACT) — can help with anxiety and daily functioning.
What if I think I have both autism and ADHD?
This is very common — the combination is often called AuDHD. Many providers offer combined assessments that assess for both conditions in the same process, which saves time and is usually cheaper than two separate assessments. Search for "AuDHD" or "combined assessment" when using Seen Sooner.
Find autism assessment providers near you
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