The functioning labels for autism spectrum disorder (ASD) aren’t part of a formal diagnosis and are considered outdated.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder. It’s caused when changes during your brain’s development affect how you learn, communicate, behave, and interact with those around you.

ASD is a disorder that occurs on a spectrum of severity, but it’s also a condition with incredibly diverse symptom presentation. This complex dynamic has made functional labels in autism outdated — and potentially harmful.

Functional labels in autism were never a part of formal diagnosis under the Diagnostic and Statistical Manual of Mental Disorders (DSM), the clinical guidebook used in the United States and many other parts of the world for diagnosing mental health conditions.

“High” and “low” functioning were informal ways of labeling the perceived level of support needed for each individual with an ASD diagnosis. While these labels were a common part of autism language at one time, they’re no longer accepted today.

Scientifically Imprecise

Scientifically, functioning labels in autism aren’t precise enough to be useful. Dr. Ryan Sultan, a board certified psychiatrist and professor at Colombia University, New York City, explains the labels oversimplify the experiences and challenges people living with ASD encounter.

“For instance,” he says, “two individuals both labeled as high functioning may have vastly different struggles, with one facing social interaction difficulties and the other grappling with sensory sensitivities.”

Putting these same experiences under one label does nothing to inform individualized treatment and person-centric care.

Sultan says the lack of clear and consistent definitions for these terms leads to confusion and misinterpretation. “They don’t effectively convey an individual’s strengths, challenges, or specific needs,” he points out.


Limiting ASD classification to external function can also diminish the importance of symptoms that don’t cause obvious functional difficulties.

Beret Loncar, the owner of Body Mechanics Orthopedic Massage in New York City, who lives with ASD, says the functioning labels in autism don’t take into account how you manage the world, if you are happy, or how you feel.

“You could be labeled high functioning because you get up every day, brush your teeth, and go to work at a very demanding job, but personally, you have no ability to be in the world with any comfort,” she says. “Internally, that is not functioning for you.”

Labeling ASD as “high function” can imply it’s less significant in someone’s life. It can minimize the challenges many people face internally.

Malorie Joy Feidner, a neurodiversity consultant from Las Vegas, Nevada, who lives with ASD, says, “I am not ‘mildly autistic.’ I do not experience autism mildly like it is a salsa. I am often burnt out and over-stimulated. But because I internalize those experiences, you experience my autism mildly.”


Sultan says functional labels in autism tend to reinforce stereotypes and stigmatization.

“People categorized as high functioning may face disbelief or inadequate support for their challenges, while those labeled as low functioning may experience low expectations that limit their growth and development opportunities,” he says.

These labels can also contribute to harmful stereotypes related to intellectual ability. High and low functioning in autism were intended to indicate someone’s capacity to perform daily tasks, but these labels are often misinterpreted by those outside the autism community as a representation of intelligence quotient (IQ).

“Living with autism spectrum disorder” or “living with ASD” are perfectly acceptable ways to refer to someone else’s autism experience. Ultimately, functional capacity and specific symptoms are very private details, usually only discussed with a doctor, mental health professional, caregiver, or loved one.

If you do need to expand on the ASD experience of another person, Sultan says the autism community has embraced more descriptive and person-centered language.

“This approach emphasizes using specific language to describe an individual’s unique strengths and challenges,” he explains. “For example, rather than using low functioning, it is more accurate to describe someone as having significant support needs. This recognizes that they may require specific forms of assistance but does not imply incapability.”

According to Fiedner, your language should be flexible and should match the preferences of the person living with ASD.

“In conversation, you might say, ‘Malorie is autistic and generally requires little support.’” she says.

The DSM-5-TR, the most recent version of the DSM, categorizes ASD based on how much support a person needs for their symptoms. The three categories take into consideration how ASD affects verbal and nonverbal social communication and how it contributes to restrictive, repetitive behaviors.

The DSM-5-TR breakdown of ASD severity is:

Level 3: Requiring very substantial support

  • difficulties with verbal and nonverbal communication skills create severe difficulties in function
  • very limited initiation of socialization
  • minimal response to social attempts from others
  • inflexibility of behavior
  • extreme difficulty coping with change
  • great distress when changing action or focus
  • restrictive and/or repetitive behaviors that significantly interfere with all aspects of function

Level 2: Requiring substantial support

  • noticeable difficulties in verbal and nonverbal social communication
  • social difficulties are present even with supports in place
  • limited initiation of socialization
  • reduced or atypical responses to social initiation from others
  • inflexibility of behavior
  • difficulty coping with change
  • distress when changing focus or action
  • restrictive and/or repetitive behaviors are observable by others

Level 1: Requiring support

  • verbal and nonverbal communication difficulties present without supports in place
  • difficulty initiating socialization
  • clear atypical or unsuccessful responses to social attempts by others
  • inflexibility of behaviors affects function in one or more situations
  • difficulty switching between activities
  • challenges with organization and planning affect independence

Functioning labels in autism spectrum disorder were once used to convey how significantly ASD affected your daily function. While they were never a formal part of an ASD diagnosis, functional labels were a common part of autism language clinically and in conversation.

Due to their inaccuracy and dismissive, stigmatizing nature, however, these terms are considered outdated. People-centric language that describes strengths, as well as individual areas of challenge, is now more widely accepted.