Guide ยท Autism
Autism levels: what level 1, 2 and 3 actually mean
An autism level describes how much support someone needs, not how autistic they are. It is a clinician's shorthand, it is rated twice, and it can change.
Updated 25 September 2026 · About 9 minutes to read · All guides
In short
- The DSM-5-TR describes three autism levels: level 1 "requiring support", level 2 "requiring substantial support" and level 3 "requiring very substantial support".
- Levels are rated separately for social communication and for restricted, repetitive behaviours, so one person can have two.
- A level describes support needs at the time of assessment, and the manual says severity can vary by context and change over time.
- "High-functioning autism" and "Asperger's" are no longer diagnostic terms; both now sit within autism spectrum disorder.
- In the NDIA's guideline, autism at level 2 or 3, diagnosed by certain clinicians, is likely to meet the disability requirements; level 1 needs more evidence of everyday impact.
The three autism levels
The levels come from the DSM-5-TR, one of the two diagnostic manuals used to diagnose autism in Australia. A clinician can add a level to describe how much support the person needs. There are three, and they are rated twice: once for social communication, once for restricted and repetitive behaviours.
| Level | What the manual calls it | Social communication | Restricted, repetitive behaviours |
|---|---|---|---|
| Level 1 | Requiring support | Without support in place, social communication differences cause noticeable problems. Starting interactions is hard, and responses to other people can be unusual or not land. | Inflexibility gets in the way in one or more parts of life. Switching between activities is hard, and trouble with organising and planning holds back independence. |
| Level 2 | Requiring substantial support | Marked differences in spoken and non-verbal communication that show even with support in place. Rarely starts interactions, and responds less, or unusually, when others approach. | Inflexibility, difficulty coping with change or repetitive behaviours happen often enough for a casual observer to notice, and get in the way across a range of settings. |
| Level 3 | Requiring very substantial support | Severe differences in spoken and non-verbal communication cause severe difficulty in daily life. Very rarely starts interactions and responds very little to others. | Inflexibility, extreme difficulty coping with change or repetitive behaviours markedly interfere with every area of life. |
Intellectual impairment and language impairment are recorded separately from the level, so a level does not tell you someone's IQ, or whether they speak.
What each level can look like in a child and an adult
These sketches follow the manual's descriptions. They are illustrations, not a checklist.
Level 1: requiring support
- In a child: talks in full sentences, but conversation does not flow back and forth. Joining in with other children is hard, and their responses can seem unexpected. Moving from one activity to the next causes friction.
- In an adult: starting social contact takes effort and can misfire. Inflexibility causes real problems in at least one area of life, and organising and planning get in the way of independence.
Level 2: requiring substantial support
- In a child: the manual's example is a child who speaks in simple sentences. They rarely start interactions, and distress at change, strict routines or repetitive movements are obvious to someone who has just met them.
- In an adult: social differences are clear even with support in place, and inflexibility or repetitive behaviours affect several areas of daily life rather than one.
Level 3: requiring very substantial support
- In a child: the manual's example is a child with few words of speech that others can understand, who very rarely starts interaction and responds little when others approach. Change is extremely hard.
- In an adult: needs very substantial support across daily life, with restricted or repetitive behaviours markedly interfering in every area.
In US surveillance data, level 3 ratings were more common among children who also had an intellectual disability.
One caution: the manual notes that autistic traits can be masked by learned strategies later in life, which is one reason the Australian guideline asks about functioning across everyday life, not just how someone comes across in an appointment.
Levels can differ between the two areas, and change over time
Because the two areas are rated separately, a report might say "level 2 for social communication, level 1 for restricted and repetitive behaviours". In practice the ratings are usually close: in one US clinic sample of 158 people, nobody was rated level 1 in one area and level 3 in the other.
The DSM-5-TR itself says severity can vary by context and fluctuate over time. Research agrees:
- A US study assessed 125 autistic children at about 3 and again at about 6. Around 29% had lower autism severity scores at 6, 17% had higher scores, and about 54% stayed roughly the same.
- A follow-up of 75 children from 6 to 11 found social communication and repetitive behaviour severity could move separately, and that these changes were linked to anxiety, ADHD and behaviour difficulties.
Both studies used a standard observation measure rather than the DSM levels, but the point carries over: a level is a snapshot. The Australian national guideline recommends assessing functioning at multiple points through life. A level on an early childhood report describes that child, at that time.
How reliable are autism levels?
Less than many people assume. The manual describes the levels in words but gives no score, cut-off or method for choosing between them.
- In 726 children, three common yardsticks of severity (autism symptoms, IQ and everyday adaptive skills) often pointed to different levels of impairment for the same child, so clinicians leaning on different measures could reach different levels.
- In 248 children across six US centres, higher levels went with younger age, lower IQ and more observed autism features, but not with emotional or behavioural problems.
- In US surveillance records for children aged 4 and 8, only 40% of autistic children had any level recorded, from about 5% to 73% depending on the site. The authors concluded this limits how useful levels are for identifying needed services.
Levels are not meaningless: in clinic samples, higher levels line up with lower adaptive skills and more autism features. But they are shorthand, not a measurement. The DSM-5-TR says the severity categories should not be used to decide eligibility for services, and that support needs can only be worked out individually.
The Australian national guideline (Autism CRC, updated 2023) recommends, alongside the diagnostic evaluation, an Assessment of Functioning covering the person's strengths and support needs across everyday life. That, more than a single number, tells you what would help.
"High-functioning" and Asperger's: why they are no longer diagnoses
Neither is a current diagnosis. The DSM-5-TR says autism spectrum disorder now covers conditions previously called high-functioning autism, Asperger's disorder and pervasive developmental disorder not otherwise specified (PDD-NOS), among others. Anyone with a well-established DSM-IV diagnosis of Asperger's should be given a diagnosis of autism spectrum disorder.
The subtypes went because clinicians could not apply them consistently. In a study of 2,102 children at 12 US university sites using the same standardised tools, sites differed in who they called autistic disorder, Asperger's or PDD-NOS.
"High-functioning" usually means autistic without an intellectual disability, and it can hide real need. A Western Australian study of 2,225 children found that, for those without intellectual disability, everyday adaptive skills were well below what their IQ would suggest. The researchers recommended dropping the term.
There is also history. Archival research published in 2018 found that Hans Asperger cooperated with Nazi-era race hygiene policies, including the child "euthanasia" program in Vienna. Some people diagnosed with Asperger's still use the word for themselves, and that is their call. A report written today will say autism spectrum disorder.
Autism levels and the NDIS
This is one place where the level does carry weight. The NDIA's Applying to the NDIS guideline has a List A of conditions likely to meet its disability requirements. It includes autism assessed under current DSM criteria as level 2 (requiring substantial support) or level 3 (requiring very substantial support), diagnosed by a specialist multidisciplinary team, paediatrician, psychiatrist or clinical psychologist experienced in assessing autism. The NDIA says that if you give it evidence of a List A diagnosis, it will likely decide you meet the disability requirements.
Autism that doesn't meet those criteria, which usually means level 1, is on List B. That list is for permanent conditions where everyday functioning varies. The NDIA will likely accept the impairment is permanent, but it will want evidence of how much autism affects daily life.
There is a tension here. The DSM-5-TR says its severity levels should not be used to decide eligibility for services, and, as above, levels are applied inconsistently. Whatever the level, the evidence that carries an application is how autism affects everyday life: communicating, socialising, learning, moving around, looking after yourself and managing your life. The NDIA's evidence guidance for autism names preferred measures of everyday functioning (the Vineland-III, WHODAS 2.0 for people 17 and over, PEDI-CAT for 16 and under) and accepts evidence from a paediatrician, psychologist, psychiatrist, occupational therapist or speech therapist. More on that in autism and the NDIS and what each report has to do.
Nobody can promise an NDIS outcome.
Questions people ask
How many levels of autism are there?
Three: level 1 (requiring support), level 2 (requiring substantial support) and level 3 (requiring very substantial support), as set out in the DSM-5-TR. Each is rated separately for social communication and for restricted, repetitive behaviours, so a person can have two different levels.
Is level 2 autism high-functioning?
No. "High-functioning" is not a diagnostic term, and level 2 means a clinician judged the person to need substantial support. Intellectual ability is recorded separately from the level, and research shows IQ is a poor guide to everyday functioning in autistic children anyway.
What is ASD level 2?
It is autism spectrum disorder rated "requiring substantial support". In the manual's description, social differences show even with support in place, and inflexibility or repetitive behaviours are obvious to a casual observer and affect a range of settings. It describes support needs at the time of assessment.
Can your autism level change?
Yes. The DSM-5-TR says severity can vary by context and fluctuate over time, and studies following autistic children have found measured severity going down for some and up for others. The Australian guideline recommends reassessing functioning at different points in life.
Does level 1 autism qualify for the NDIS?
It can, but not automatically. The NDIA's guideline puts autism at level 2 or 3, diagnosed by certain clinicians, on its list of conditions likely to meet the disability requirements. Autism that doesn't meet those criteria, usually level 1, is on a second list, where you need evidence that autism substantially affects everyday life. The rules change from 1 January 2028, including for children aged 8 and under.
Is Asperger's the same as level 1 autism?
Not officially. Asperger's is no longer diagnosed, and the DSM-5-TR says people with a well-established Asperger's diagnosis should be given a diagnosis of autism spectrum disorder without mapping them to a level. Any level given today depends on current support needs.
Wondering whether an assessment makes sense? The free screener takes about three minutes, for your child, your adult son or daughter, or yourself. It suggests which assessment fits, and it will tell you if one does not look like the right next step. Start the free screener.
Where this information comes from
We would rather you checked us than took our word for it. Every link below is the original source, not a summary of one.
- Autism Aspergers Advocacy Australia (A4). Autism Spectrum Disorder (ASD) in the DSM-5-TR.Australian advocacy organisation's reproduction of the DSM-5-TR autism criteria and severity table, including the statements that severity is rated separately for each domain, can fluctuate over time and should not be used to determine eligibility for services.
- Weitlauf et al. (2014). Brief report: DSM-5 "levels of support": a comment on discrepant conceptualizations of severity in ASD. Journal of Autism and Developmental Disorders.US registry study of 726 children showing that autism symptom, IQ and adaptive measures of severity often disagreed, and that the DSM-5 gave no method for choosing a level.
- Gardner et al. (2018). Correlates of DSM-5 autism spectrum disorder levels of support ratings in a clinical sample. Journal of Autism and Developmental Disorders.US clinic study of 158 people finding levels tracked adaptive skills and autism severity, with no one rated level 1 in one domain and level 3 in the other.
- Mazurek et al. (2019). Factors associated with DSM-5 severity level ratings for autism spectrum disorder. Autism.Study of 248 children at six US Autism Treatment Network sites linking higher levels to younger age, lower IQ and observed autism severity, but not emotional or behavioural problems.
- Russell et al. (2026). Prevalence of autism spectrum disorder severity levels from the fifth edition of the Diagnostic and Statistical Manual (DSM-5) in the Autism and Developmental Disabilities Monitoring Network. Journal of Autism and Developmental Disorders.US population surveillance study finding only 40.4% of autistic children aged 4 and 8 had a level recorded, with wide variation between sites.
- Waizbard-Bartov et al. (2021). Trajectories of autism symptom severity change during early childhood. Journal of Autism and Developmental Disorders.US longitudinal study of 125 autistic children assessed at about 3 and 6, finding severity decreased for 28.8%, stayed stable for 54.4% and increased for 16.8%.
- Waizbard-Bartov et al. (2024). Changes in the severity of autism symptom domains are related to mental health challenges during middle childhood. Autism.US longitudinal study of 75 autistic children aged 6 to 11 showing social communication and repetitive behaviour severity changed separately and in step with anxiety, ADHD and behaviour problems.
- Alvares et al. (2020). The misnomer of 'high functioning autism': intelligence is an imprecise predictor of functional abilities at diagnosis. Autism.Western Australian register study of 2,225 children finding adaptive skills fell well below IQ for autistic children without intellectual disability, and recommending the term be dropped.
- Lord et al. (2012). A multisite study of the clinical diagnosis of different autism spectrum disorders. Archives of General Psychiatry.Study of 2,102 children at 12 US sites showing clinics could not reliably distinguish autistic disorder, Asperger's and PDD-NOS, supporting the move to a single autism diagnosis.
- Czech (2018). Hans Asperger, National Socialism, and "race hygiene" in Nazi-era Vienna. Molecular Autism.Archival historical study documenting Hans Asperger's cooperation with Nazi-era race hygiene policies and the child euthanasia programme.
- Autism CRC (2023). National Guideline for the Assessment and Diagnosis of Autism in Australia (updated edition).Australia's national guideline, approved by the CEO of the NHMRC on 8 December 2023, recommending an Assessment of Functioning covering strengths and support needs, repeated through life.
- NDIS. What are examples of disability evidence?The NDIA's own list of accepted evidence for autism: which professionals, the DSM-5, and preferred functional measures (Vineland-III, WHODAS 2.0, PEDI-CAT).
- NDIS. What are the NDIS disability requirements?The NDIA's statement of the disability requirements, including permanence and the six areas of functional capacity.
- National Disability Insurance Agency (2026). Applying to the NDIS (guideline dated 26 August 2026).The NDIA's access guideline, including List A (autism at level 2 or 3, diagnosed by specified clinicians) and List B (autism not meeting those criteria).
- Department of Health, Disability and Ageing (2026). About the changes to the NDIS.Government summary of the changes, including the October 2026 budget reset and the 2028 access changes for young children.
- Department of Health, Disability and Ageing. About Thriving Kids.Who Thriving Kids is for, that no diagnosis is needed, and the rollout from October 2026 to 1 January 2028.
Links to external sites are provided for reference. We do not control them and they may change. Last checked 25 September 2026.
This guide is general information, not medical advice. If you are worried about yourself or your child, talk to your GP.
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