Understanding the Levels of Autism Spectrum Disorder

Autism spectrum disorder impacts how a person perceives the world and interacts with others. The levels of autism help professionals determine the right amount and type of support they can provide autistic individuals.

In this guide, you’ll learn what characterizes the different levels of autism and what type of support an individual might need.

What is Autism Spectrum Disorder?

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition affecting brain development and characterized by difficulties with social interaction and repetitive behaviors. As per the CDC, ASD occurs in one in 36 children [*].

The potential early indicators of ASD include:

• Inability to make eye contact
• Few shared interests with peers
• Delayed speech, repetitive language
• Obsessive interests
• Unusual reactions to external stimuli
• Difficulties managing change

These indicators are typically observed in children as young as three.

The two core areas in which people with ASD may experience significant differences include persistent deficits in social communication and restrictive/repetitive patterns of behavior.

How Many Levels of Autism are There?

According to the DSM-5, there are three levels of autism varying in the severity of symptoms and need for support. Below, we break down each level.

Level 1: Requiring Support

Level 1 autism is sometimes considered “mild” or the “least severe,” meaning a person still has high executive functioning. While they may struggle to maintain positive social interactions, they can often express themselves verbally.

Key Characteristics of Level 1 Autism

• Challenges initiating conversations with others
• Challenges staying engaged in conversations
• Display of rigid behavioral patterns
• Difficulties with changes and new environments
• Difficulties with organization and planning
• Interference with functioning, such as switching tasks

Support for Level 1 Autism

Support for individuals with Level 1 autism typically includes:

• School accommodations: At school, a child may receive an Individualized Education Program (IEP), which provides accommodations such as extra time for tests or visual aids.
• Speech-language therapy: Therapists work to enhance a child’s verbal and nonverbal communication skills.
• Occupational therapy: Practitioners focus on practical life skills, such as writing, dressing, and managing sensory challenges.

Level 2: Requires Substantial Support

People with level 2 autism require more substantial support, as they may struggle more significantly in social settings. They may exhibit stimming behaviors, which can hinder their ability to complete tasks.

Key Characteristics of Level 2 Autism

• Speaking in short sentences
• Discussing niche or hyper-specific topics
• Repetitive behaviors, such as skin-picking, leg shaking, or thumb twiddling
• Difficulties understanding nonverbal communication, such as facial expressions or hand gestures

Support for Level 2 Autism

Level 2 autism requires greater support, which may include the following:

• Applied Behavior Analysis (ABA): This therapy focuses on reducing challenging behaviors and teaching functional skills through the use of positive reinforcement.
• Support devices: In cases where an individual with Level 2 autism struggles to communicate verbally, therapists might equip them with alternative communication devices (AAC), such as iPads or speech-generating devices (SGDs).

Level 3: Requiring Very Substantial Support

Someone with level 3 autism may require accommodations in their daily life, including at home, school, and in the community, to function independently. They might have frequent meltdowns, display signs of aggression, or self-harm when they are under duress.

Key Characteristics of Level 3 Autism

• Limiting or avoiding interactions with others
• Inability to engage in imaginative play with peers
• Limited interest in friendships and difficulties forming relationships
• Extreme difficulties managing changes
• Repetitive behavioral patterns
• High levels of distress

Support for Level 3 Autism

Level 3 autism requires the highest level of support, which includes the following:

• In-house caretaker: A caretaker is responsible for creating a structured and sensory-friendly environment. They help establish predictable routines and make sensory modifications to the individual’s environment, such as limiting bright lights, loud noises, and other irritants.
• Additional therapies: Besides ABA, other therapies for individuals with Level 3 autism include sensory integration therapy, speech therapy, physical therapy, and occupational therapy.

Are There Other Types of Autism?

Yes, other types of autism spectrum disorders come with social, communication, and behavioral challenges. Here are a few examples:

Asperger’s syndrome

Asperger’s syndrome is a milder form of autism characterized by high intelligence and a deep interest in niche topics. Individuals with Asperger’s syndrome may discuss these topics nonstop and show little interest in anything else.

PDD-NOS

Pervasive developmental disorder (not otherwise specified) was once a category of autism characterized by poor social skills, difficulties interacting with people, problems with communication, and other stereotyped behavior. In 2013, the American Psychiatric Association phased out the term, and it is no longer considered a diagnosis.

Autistic Disorder

Autistic disorder is a now-outdated term under the autism spectrum disorder umbrella. It was previously characterized primarily by difficulties in social interactions and communication. Today, we use “spectrum” to acknowledge that autism can affect people in different ways.

Childhood Disintegrative Disorder

Also called Heller syndrome, childhood disintegrative disorder (CDD) refers to a condition characterized by normal development and the eventual decline of previously learned skills. As someone with CDD grows older, they might experience regression in language, social skills, and motor skills, and may even develop incontinence.

Rett Syndrome

Rett syndrome is a rare genetic neurological disease that causes the progressive loss of motor skills and language. This condition is more common in females and can potentially cause seizures and intellectual disabilities.

How Autism Levels are Diagnosed

Medical professionals diagnose autism levels through observation, parent interviews, reviewing medical records, and standardized tools like the DSM-5. In most children, signs of autism can start appearing by age two, though diagnosis can happen earlier or later.

There are two stages to diagnosing a potentially autistic child. The first stage is a developmental checkup, which occurs at 18 and 24 months of age. During these sessions, a professional will observe the child’s behavior, development, and family medical history.

The second stage of diagnosis is the additional evaluation. These evaluations may involve using tools such as the Autism Diagnostic Observation Schedule (ADOS) or Childhood Autism Rating Scale (CARS) for cognitive assessment [*].

Outlook

The outlook for individuals with autism will vary according to the amount of support they need. Individuals with Level 1 autism have the highest chance of success and are often able to live independently and pursue healthy careers. Early intervention may be enough to guarantee a high quality of life.

On the other hand, individuals with Level 2 autism may require ongoing therapies and household support, though they can still develop valuable life skills and meaningful connections.

While the challenges an individual experiences with Level 3 autism are constant and sometimes unforgiving, consistent therapy and household support can lead to increased independence. However, they may need help coping with daily life and continue to experience severe deficits in communication.

The Bottom Line

Categorizing autism symptoms into levels can help families determine what type of support their loved one requires. While any level of autism can be challenging to live with, early assessment and intervention can significantly increase one's chances of enjoying independence and meaningful relationships.

Check out our collection of worksheets to find activities across different mental health topics to engage and inspire children of all abilities..

FAQs About Autism Levels

Can someone move between autism levels over time?

Yes, someone can move between autism levels over time as their need for support changes. Environmental factors and maturation play a significant role in determining the level of support an autistic person requires throughout their life [*].

Can someone with Level 3 autism live independently?

Someone with Level 3 autism may require lifelong support, though they can perform many tasks individually, given that they receive early intervention and effective therapies.

How do co-occurring conditions (like ADHD or anxiety) affect autism levels?

Co-occurring conditions like ADHD or anxiety can exacerbate autistic symptoms. For example, someone with anxiety and autism might have heightened sensory sensitivities and struggle more with ritualistic behaviors [*].

Sources:

1. CDC. “Data and Statistics on Autism Spectrum Disorder. Autism Spectrum Disorder (ASD).” 2025.
2. Park HS, Yi SY, Yoon SA, Hong SB. “Comparison of the Autism Diagnostic Observation Schedule and Childhood Autism Rating Scale in the Diagnosis of Autism Spectrum Disorder: A Preliminary Study.” Journal of Korean Academy of Child and Adolescent Psychiatry, 2018.
3. Einat Waizbard-Bartov, Miller M. “Does the severity of autism symptoms change over time? A review of the evidence, impacts, and gaps in current knowledge.” Clinical Psychology Review, 2022.
4. Leitner Y. “The Co-Occurrence of Autism and Attention Deficit Hyperactivity Disorder in Children: What Do We Know?” Frontiers in Human Neuroscience, 2014.