Understanding the Different Levels of Autism

Written by Dr. Simon Khela MBChB MRCGP, GMC Registered Doctor 

‍

There are three autism support levels in the DSM-5-TR: Level 1, requiring support; Level 2, requiring substantial support; and Level 3, requiring very substantial support. These levels describe the amount of support a person may need with social communication and restricted or repetitive behaviours.

Autism is a spectrum, which means it affects every person differently. Two autistic people assigned the same support level may have very different strengths, communication styles, sensory needs and day-to-day experiences. A level is therefore not a complete description of an individual.

The three-level framework comes from the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision, commonly known as the DSM-5-TR. It is important to understand that these are support levels, not fixed stages that every autistic person progresses through.

In this guide, we explain:

•       How many levels of autism there are

•       What Levels 1, 2 and 3 mean

•       The differences between the three support levels

•       Whether autism levels are used in the UK

•       Why some people refer to stages, degrees or types of autism

•       Whether a person's support needs can change over time

What Are the Three Levels of Autism?

The three autism support levels are:

1. Level 1 autism, requiring support

2. Level 2 autism, requiring substantial support

3. Level 3 autism, requiring very substantial support

The DSM-5-TR considers support needs in two principal areas: social communication and social interaction, and restricted or repetitive behaviours, interests or activities.

A clinician considers how a person communicates, responds to social situations, manages changes, organises daily activities and experiences repetitive behaviours or focused interests. Support needs may differ between the two areas and may also vary across home, education, work and community settings.

Autism Levels at a Glance

These descriptions are broad examples, not a checklist. They should not be used to diagnose yourself or another person.

Autism Level 1 vs Level 2 vs Level 3

The main difference between Autism Levels 1, 2 and 3 is the amount of support a person is assessed as needing, not how "autistic" they are or their value, intelligence or potential.

Level 1 describes someone who requires support. Level 2 describes someone who requires substantial support. Level 3 describes someone who requires very substantial support. However, a person's support needs can vary by situation, life stage, stress levels, physical or mental health and access to appropriate accommodations.

Communication ability should not be used as a measure of intelligence. Some non-speaking or minimally speaking autistic people understand considerably more than they can express verbally.

Level 1 Autism: Requiring Support

Level 1 autism is the DSM-5-TR category described as "requiring support". It is sometimes informally called mild autism or high-functioning autism, but those descriptions can be misleading because they may minimise significant support needs.

These characteristics often overlap with general signs of autism in adults, though presentation varies widely between individuals.

Possible characteristics of Level 1 autism

A person with Level 1 autism may:

•       Find back-and-forth conversation difficult

•       Have difficulty interpreting tone of voice, facial expressions or unwritten social rules

•       Want friendships but find initiating or maintaining them challenging

•       Feel distressed or overwhelmed by unexpected changes

•       Have highly focused interests

•       Need help with planning, organisation or switching between tasks

•       Mask or hide autistic traits in some social situations

•       Experience sensory sensitivities that are not obvious to other people

Example: A person may communicate fluently about a favourite subject but find small talk, group conversations or unfamiliar social situations exhausting. They may appear independent while still needing meaningful support with planning, sensory regulation or managing change, read our guide to recognising signs of autism in adults for a fuller picture of how this can present.

Level 1 does not mean that the person's experiences are always mild. Their needs may be less visible, particularly if they have learned to mask their difficulties.

Level 2 Autism: Requiring Substantial Support

Level 2 autism means that a person has more noticeable support needs relating to social communication, flexibility and repetitive behaviours. These differences are generally apparent even when some support is already in place.

In children, these needs are sometimes identified alongside broader signs of autism in children.

Possible characteristics of Level 2 autism

A person with Level 2 autism may:

•       Use shorter sentences or communicate mainly about particular needs and interests

•       Find it difficult to initiate or respond to social interaction

•       Have difficulty interpreting facial expressions, gestures or social expectations

•       Display repetitive movements or behaviours that are noticeable to others

•       Become significantly distressed by changes in routine

•       Need regular assistance with education, employment or daily activities

•       Require visual supports, communication adjustments or help preparing for transitions

•       Experience sensory differences that affect participation in everyday environments

Example: A child may communicate confidently about trains but find open-ended conversation difficult. They may require substantial preparation before a change in routine and additional support to participate in school or community activities, our guide to early signs of autism in children covers what this can look like at a younger age.

Level 2 does not describe one fixed profile. Some people may have strong verbal abilities while requiring substantial support in other areas, such as sensory regulation, flexibility or independent living.

Level 3 Autism: Requiring Very Substantial Support

Level 3 autism describes very substantial support needs. A person may experience significant barriers to communication, social interaction, flexibility and participation in everyday activities.

Possible characteristics of Level 3 autism

A person with Level 3 autism may:

•       Use few spoken words, no spoken language or an alternative communication method

•       Rarely initiate social interaction without support

•       Find it very difficult to respond to social approaches

•       Experience extreme distress when routines or expectations change

•       Display repetitive behaviours that significantly affect daily activities

•       Require extensive support with personal care, safety or daily living

•       Use communication aids, pictures, signs, gestures or an augmentative and alternative communication device

•       Need highly structured environments and consistent support

Example: A person may communicate through gestures, pictures or a communication device and require extensive support to cope with transitions, sensory demands and daily routines.

Level 3 should not be interpreted as meaning that a person cannot learn, communicate, form relationships or enjoy a meaningful life. The right support should respect the person's communication style, autonomy, preferences and strengths.

How Are Autism Support Levels Determined?

Autism support levels are assigned through a clinical assessment rather than an online test or a single list of symptoms. Clinicians consider the person's developmental history, communication, behaviour, daily functioning and the impact of their differences across different settings.

The DSM-5-TR considers support needs separately in:

1. Social communication and social interaction

2. Restricted and repetitive behaviours

A person may therefore have greater support needs in one area than another. Factors such as language ability, learning disability, ADHD, anxiety, sensory processing, physical health and the person's environment may also affect the support they need, but they are not fully described by an autism level.

An autism level should never replace an individualised assessment of strengths, needs and appropriate support.

Are Autism Levels Used in the UK?

The three numbered support levels come from the DSM-5-TR, which is published by the American Psychiatric Association. Some UK clinicians and services may refer to this framework, but not every autism diagnosis in the UK is assigned a numbered level.

UK assessments are generally expected to describe the individual's autistic characteristics, strengths and areas in which support may be helpful. This approach sits within the government's own National Strategy for Autistic Children, Young People and Adults 2021 to 2026, which focuses on individualised understanding, education access and community support rather than a numbered severity scale.

Therefore, a person diagnosed with autism in the UK may not be told that they have "Level 1", "Level 2" or "Level 3" autism. This does not make their diagnosis incomplete or less valid. Different services may describe support needs in different ways.

Are Autism Levels the Same as Stages, Degrees or Tiers?

No. Autism levels are not developmental stages through which a person progresses.

People sometimes search for stages of autism, degrees of autism, tiers of autism, autism severity scale, or autism categories.

These phrases are often informal ways of referring to the three DSM-5-TR support levels. However, "stages" is not the most accurate term because autism does not follow a predictable sequence from Level 1 to Level 2 or Level 3.

The levels describe a clinician's assessment of current support needs. They do not represent a ladder, a score of personal ability or a prediction of someone's future.

Are There Five Levels of Autism?

No. There are not five official DSM-5-TR autism levels. The current DSM framework describes three support levels.

Confusion about "five levels of autism" may come from the DSM-IV, which previously grouped five diagnoses under the broader category of pervasive developmental disorders. These were diagnostic categories, not five levels of severity.

The former categories included:

•       Autistic disorder

•       Asperger's disorder

•       Pervasive developmental disorder not otherwise specified

•       Childhood disintegrative disorder

•       Rett's disorder

When the DSM-5 was introduced in 2013, autistic disorder, Asperger's disorder and pervasive developmental disorder not otherwise specified were brought together under the diagnosis of Autism Spectrum Disorder. Rett syndrome is recognised as a separate genetic condition, and childhood disintegrative presentations are no longer treated as a separate autism level.

Can an Autism Support Level Change Over Time?

A person's assessed support needs may change over time, but autism itself is lifelong.

Support requirements can be influenced by:

•       Age and life stage

•       Education or employment demands

•       Stress and mental health

•       Physical health

•       Communication development

•       Living environment

•       Access to appropriate accommodations

•       Burnout, masking or major life changes

A person may need less support in one setting and considerably more in another. For example, someone may manage well at home but require substantial adjustments at school or work. Another person's needs may increase during illness, bereavement, transition or autistic burnout.

A change in support needs does not mean that the person has become "more" or "less" autistic or that autism has been cured. Autism is a lifelong developmental difference.

Do Autism Levels Describe Every Support Need?

No. An autism support level provides only a broad description of needs in the two core DSM diagnostic domains. It does not fully describe the whole person.

A support level does not, by itself, explain:

•       Intelligence or learning ability

•       Spoken-language ability

•       Sensory processing differences

•       Emotional regulation

•       Mental health

•       Physical health

•       Personal care needs

•       Education or employment ability

•       Safety awareness

•       Strengths, interests or preferences

Two people with the same support level may need completely different adjustments. Individualised support planning is therefore more useful than relying on a level alone.

Why Understanding Autism Support Needs Matters

Understanding autism support needs can help families, carers, schools, employers and healthcare professionals provide appropriate adjustments.

Support may include:

•       Clear and direct communication

•       Predictable routines

•       Visual timetables or written instructions

•       Sensory adjustments

•       Speech and language therapy

•       Occupational therapy

•       Support at school or work

•       Help with planning and independent living

•       Augmentative and alternative communication

•       Reasonable adjustments to appointments and environments

The purpose of identifying support needs should be to improve wellbeing, communication, participation and autonomy, not to place limits on what an autistic person may achieve.

Need professional guidance? Our Private GPs can discuss your concerns, explain possible next steps and arrange an appropriate referral for an autism assessment where clinically indicated. If ADHD traits are also present, our comparison of AuDHD vs ADHD may also be helpful, and a broader mental health assessment can be arranged where appropriate.

Final Thoughts

Autism is incredibly diverse, and no two autistic people are exactly the same.

The DSM-5-TR describes three autism support levels: Level 1, requiring support; Level 2, requiring substantial support; and Level 3, requiring very substantial support. However, these levels are broad clinical descriptions rather than complete profiles of an individual.

They should not be treated as fixed stages, measures of intelligence or predictions of someone's future. In the UK, a diagnostic report may focus on a person's individual strengths and support needs without assigning a numbered level.

At Private Medical Clinic, we are passionate about helping autistic children, teenagers and adults access appropriate advice and support. Whether you are considering an autism assessment, seeking an ADHD referral, or looking for ongoing clinical guidance, our team is here to help.

Book an Autism Assessment Near You

•       Autism Testing Birmingham

•       Autism Testing London

•       Autism Testing Newcastle

•       Autism Testing Leicester

•       Autism Testing Sutton Coldfield

•       Autism Testing Bournemouth

•       Autism Testing Oxford

•       Autism Testing Derby

See our current fees, contact us to discuss your concerns and learn more about the assessment and referral options available, or browse our FAQs for more general questions.

Frequently Asked Questions