Understanding the Three Levels of Autism

There are three levels of autism spectrum disorder (ASD), which are described in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). These levels replicate functioning labels (low vs. high functioning) as they do not account for people who exhibit traits associated with multiple levels daily nor for people who fluctuate between levels day-by-day.

However, these levels are important to be aware of because of they are legitimate to the medical community and subsequently impact the lives of autistic people. The three levels can be used as a springboard to better understand that autistic people have a variety of presentations.

Each person with an ASD diagnosis is further labeled with either ASD level 1, level 2, or level 3, depending on how incompatible their autistic traits are with neurotypical expectations and how much support they need in their daily life. The levels range from least to most incompatible.

This article discusses the traits that are typical of each of the three ASD levels. It also includes realistic examples of the experiences that are associated with each level.

3 functional levels of autism

Verywell / Cindy Chung

The DSM's Three Levels of Autism

Autism spectrum disorder affects how a person acts, experiences the world, and expresses themselves. While autistic people have similarities, each individual is different and so is their presentation of being autistic.

The three levels of ASD help medical providers prescribe appropriate therapies based on a person's unique needs. These therapies can help the person with ASD make the most of their strengths and improve their social, language, and occupational skills.

It is important to keep in mind that actual autistic people's traits and experiences are not as clearcut as these levels present. Many autistic people have a wide mix of traits associated with multiple levels, so these classifications are not helpful outside of medical contexts. Labelling an autistic person as one level socially and seeing them solely through the lens of the DSM can lead to neglect, hindered potential, and harmful misunderstandings.

The previous version of the DSM, the DSM-4, divided autism into five distinct diagnoses ranging from Asperger's syndrome (no longer used due to it originating from a Nazi scientist for use in the field of eugenics) to autistic disorder, which indicated "severe autism." The DSM-5 combines all of these into the single diagnosis of ASD, but with three different levels.


Both of these categorizations describe autistic people via a medical and neurotypical lens, and differ from autistic people's descriptions of themselves and their experiences of neurodivergence.

Level 1: Requires Support

Level 1 ASD describes people who do not need a lot of support. People with level 1 ASD may have a hard time communicating with neurotypical people, including their peers. For example, they may not say the right thing at the right time or be able to read social cues and body language.

A person labeled with ASD level 1 is usually able to communicate in full sentences most of the time, but may have trouble engaging in extended, back-and-forth communication with neurotypical people. They are likely to have social anxiety and may experience burnout from long term masking, or acting neurotypical.

They may also have trouble moving from one activity to another or trying new things. Additionally, they may have problems with organization and planning, and independence for them may differ from neurotypical expectations for people their age.

Level 2: Requires Substantial Support

People diagnosed with ASD level 2 have a harder time masking than those diagnosed with level 1 and may find it hard to communicate or socialize in ways that are accepted or understood by neurotypical society. Likewise, they will find it harder to change focus or shift from one activity to the next.

The DSM's level 2 expression of autism includes people who have very specific interests and who engage in repetitive behaviors that veer far from accepted, neurotypical behaviors or that appear in spaces neurotypical people view as incongruous.

For example, an autistic child or adult may pace back and forth during a class or meeting, or say the same thing over and over again. These behaviors are types of stimming, self-stimulation, that autistic people use to regulate themselves internally. Neurotypical people stim as well by humming, tapping their feet or fingers, dancing, etc.

One reason autistic people stim more is because most of our society was not built with neurodivergent people in mind. Hence, the regulation that is typically covered by societal infrastructure for neurotypical people has to be handled by autistic individuals and their loved ones. Autistic people who express level 2 and 3 traits have a larger burden of self-regulation.

Level 3: Requires Very Substantial Support

People with level 3 diagnoses need the most support and are subsequently at very high risk for neglect, abuse, and discrimination. People in this category will have many of the same traits as those with levels 1 and 2 diagnoses, but are entirely unable to mask and have very high burdens of self-regulation.

Problems expressing themselves accurately both verbally and with body language or facial expressions can make it very hard to complete daily living tasks, interact socially, and deal with a change in focus or location. Some of these difficulties can be assuaged with early access to augmentative and alternative communication (AAC) devices, as communication is a human right everyone should have access to even if they do not speak. Engaging in repetitive behaviors is another trait of level 3 ASD.

A person with an ASD level 3 diagnosis is more likely to have communication differences and may rarely initiate interactions, especially with neurotypical people. When they do, they are likely to be perceived as awkward. They may be more comfortable with or prefer parallel play instead of interactive hangouts, or might prefer to interact with other based upon scripts.

Limitations of ASD Levels

Although the DSM's ASD levels are useful for figuring out a person's support needs, the categories don't give a full picture of the capacities, strengths, and needs of each individual autistic person.

The three levels do not entirely encompass the traits and lived experiences of all autistic people nor does the DSM's description of an autistic person diagnosed as level 1 paint an accurate picture of who that person is. The DSM-5 offers little specificity regarding the types of support that individuals need or situations when support is needed.

For example, some autistic people need accommodations at school but are fine at home, while others may do well at school but struggle in social situations.

What's more, the level a person is assigned when they're first diagnosed can shift as they develop and refine their social skills, and as anxiety, depression, trauma, burnout, and other issues common among autistic people change or grow more severe.

Assigning people to one of the three levels of autism can be useful for understanding what types of services and supports would serve them best.

It won't, however, predict or account for unique details in their personality and behavior, which means the support and services they receive will need to be highly individualized.

Summary

The DSM-5 is an important manual used by doctors to diagnose people with autism spectrum disorder. It describes three levels of ASD, which range in traits and in how much support the autistic person needs in daily life.

The three ASD levels give a basic outline of the ways autistic people may communicate, socialize, and behave. This way of diagnosing autistic people does not, however, fully address the diverse array of lived experiences autistic people have.

Frequently Asked Questions

  • What are the different levels of autism?

    An autism spectrum disorder diagnosis is broken into levels 1, 2, and 3. These levels indicate the extent to which autism impacts an individual's ability to communicate and take care of themselves as deemed appropriate by neurotypical society. The levels describe traits and detail how much support a person might need. 

  • Do children with level 1 autism need a classroom aide?

    Possibly, though each autistic person is different.


    Some people diagnosed with level 1 autism may have difficulty in a mainstream classroom due to sensory challenges and are more comfortable in a smaller class setting. Others may be comfortable in a general education classroom without an aide, while some may need a one-on-one or shared aide to help keep them on track.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Autism Spectrum Disorder Diagnostic Criteria.

  2. Weitlauf AS, Gotham KO, Vehorn AC, et al. Brief report: DSM-5 "levels of support:" A comment on discrepant conceptualizations of severity in ASD. J Autism Dev Disord. 2014;44(2):471-6. doi:10.1007/s10803-013-1882-z

  3. Masi A, Demayo MM, Glozier N, et al. An overview of autism spectrum disorder, heterogeneity and treatment options. Neurosci Bull. 2017;33(2):183-193. doi:10.1007/s12264-017-0100-y

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.