What Are the Three Levels of Autism?

Autism is a "spectrum" disorder, meaning that a person with autism can be mildly, moderately, or severely autistic.  What's more, while everyone with autism shares certain core symptoms, many people also have additional intellectual, emotional, or language impairments.

Since everyone with autism now receives the same diagnosis of autism spectrum disorder (ASD), the creators of the official Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) identified three levels of the disorder, according to severity. This helps clinicians provide a more specific diagnosis and also helps those involved in the care of people with autism have a clearer understanding of a person's strengths and limitations.

The three levels reflect a person's ability to communicate, adapt to new situations, expand beyond restricted interests, and manage daily life. People at level 1 need relatively little support, while people at level 3 need a great deal of support.

3 functional levels of autism
Illustration by Cindy Chung, Verywell

Until 2013, the DSM described the autism spectrum as a disorder that included five distinct diagnoses. Asperger's syndrome, for example, was essentially a synonym for "high-functioning autism," while "autistic disorder" meant almost the same thing as "severe autism."

ASD Levels of Support

The autism spectrum is incredibly wide and varied. Some people with autism have above-average intelligence, while others are intellectually disabled. Some have severe communication problems, while others communicate effectively.

Here's how the three functional levels, each of which is defined based on the amount of support a specific person requires to function in the general community, are defined:

ASD Level 1: Requiring Support

Without supports in place, a person with ASD level 1 will have noticeable difficulties with social communication. They may have little interest in social interactions, have difficulty initiating social interactions, and respond inappropriately to the social overtures of others.

Someone with level 1 may be inflexible in certain ways and have difficulties switching between activities; they may also have problems with organization and planning that can hamper independence.

A person with level 1 ASD is usually able to speak in full sentences and communicate, but has trouble engaging in back-and-forth conversation with others. In addition, attempts at making friends are typically unsuccessful.

ASD Level 2: Requiring Substantial Support

People with ASD level 2 may show marked deficits in verbal and nonverbal social communication skills and problems with social communication that are apparent even with supports in place. They may avoid initiating social interactions and have reduced or abnormal responses to social overtures from others.

Inflexibility of behavior, difficulty coping with change, or other restricted/repetitive behaviors appear frequently enough to be obvious to the casual observer and interfere with functioning in a variety of contexts. Those at level 2 may also experience distress and/or difficulty changing focus or action.

A person diagnosed with ASD level 2 speaks in simple sentences, is limited to narrow special interests, and displays markedly atypical forms of nonverbal communication.

ASD Level 3: Requiring Very Substantial Support

At this level, severe deficits in verbal and nonverbal social communication skills cause severe impairments in functioning, very limited initiation of social interactions, and minimal response to social overtures from others.

Inflexibility of behavior, extreme difficulty coping with change, or other restricted/repetitive behaviors markedly interfere with functioning in all spheres. A person with ASD level 3 may experience great distress and difficulty when required to change their focus or action.

A person with ASD level 3 will have a very limited ability to speak intelligibly and will rarely initiate interactions. When they do initiate an interaction, they will do so awkwardly. Someone at level 3 will also respond only to very direct social approaches on the part of other people.

Limitations of ASD Levels

While the ASD levels of support are useful for indicating where someone diagnosed with ASD falls on the autism spectrum, it is still not always easy for clinicians to assign a level. What's more, assignment of levels can be somewhat subjective and lacking in nuance. It's also possible for someone to change levels over time as their skills improve and other issues (such as anxiety) decrease.

Some questions that may arise as you consider ASD levels:

  • What type of support did the American Psychiatric Association have in mind when it developed these functional levels? A personal care assistant? A 1:1 school aide? A job coach? A college advisor?
  • In which situations do people at various levels require support? Some people with autism do fine at home but need help in school (where demands are specific and intense). Other people with autism do well at school but need help in social and work settings.
  • Some people with autism have received sufficient therapy to appear more or less typical when interviewed by a single adult but have significant issues when interacting with peers. What type of support might they need?
  • Do the levels of support refer back, in any way, to services provided? (The answer, so far, appears to be “sometimes.”)
  • Anxiety is a very common trait among people with higher-functioning autism, and this can cause extreme challenges in typical settings. If a person is bright, verbal, and academically capable, but anxious and depressed—and thus in need of significant support in order to function in a job or school—where do they fit into the picture?

A Word From Verywell

If your child (or you, or another loved one) has been diagnosed with autism spectrum disorder, being assigned one of the three levels can be useful for understanding how high- or low-functioning they are likely to be and what types of services and supports to pursue. Keep in mind, however, that each person with autism is an individual with nuances in personality and behavior. Hence, supports and services should be tailored to meet the specific needs of that person to the extent possible.

Was this page helpful?
Article 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. Faras H, Al ateeqi N, Tidmarsh L. Autism spectrum disorders. Ann Saudi Med. 2010;30(4):295-300. doi:10.4103/0256-4947.65261

  2. Autism Speaks. Autism Diagnosis Criteria: DSM-5.

  3. 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

  4. 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

Additional Reading