If you’re wondering how autism spectrum disorder (ASD) is classified or how many levels or classifications of autism there are, you’re not alone. The way autism is understood, diagnosed, and described has changed significantly over the years.

These changes can leave you with questions like, “What are the current classifications of autism?” or “Is there a term that has replaced Asperger’s syndrome?” Whether you’re newly diagnosed, supporting a loved one, or just trying to understand more, here’s what you need to know about how autism is defined today.

How Autism Spectrum Disorder Diagnosis Has Changed

In 2013, the American Psychiatric Association released the fifth version of its Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM-5-TR. This is important to people and families affected by autism because it changed the way the condition is diagnosed.

The DSM-5-TR eliminated several previously separate diagnoses — including Asperger’s syndrome and pervasive developmental disorder–not otherwise specified (PDD-NOS) — and grouped them under a single diagnosis: autism spectrum disorder.

Instead of using different names for different kinds of autism, the DSM-5-TR recognized that autism is a spectrum. This means it can look very different from person to person, depending on how and when symptoms appear, and what kinds of support someone needs.

Clarifications in the DSM-5-TR

In 2022, the DSM was updated again with a version called the DSM-5-TR, where “TR” stands for text revision. This update didn’t change the autism diagnosis itself, but it made the language clearer for professionals.

For example, it clarified that both sets of symptoms must be present for a diagnosis:

• Ongoing difficulties with social interaction or communication, starting in early childhood
• Repetitive behaviors or restricted interests, including sensory differences (like being overwhelmed by sounds or seeking certain textures)

The DSM-5-TR also helped reduce confusion between autism and other developmental conditions like intellectual disability or language disorders, which can occur alongside ASD but are not the same thing.

Diagnoses Replaced by ASD

Before the DSM-5, four different diagnoses were used for what we now call autism spectrum disorder. These were:

• Autistic disorder
• Asperger’s syndrome
• Childhood disintegrative disorder
• PDD-NOS

All of these terms have been eliminated, replaced with the single diagnosis of autism spectrum disorder. However, many families still use or identify with these older terms, and they may reflect real differences in how autism shows up for different people.

What Symptoms Are Required for an Autism Diagnosis?

To receive a diagnosis of autism spectrum disorder, a person must show both:

• Difficulties in social interaction or communication that began in early childhood
• Restricted, repetitive patterns of behavior, activities, or interests — which may include sensory sensitivities (like being bothered by certain lights, sounds, or textures)

Because these symptoms can vary widely in how they appear, no two autistic people are exactly alike.

What To Know About Social Communication Disorder

The DSM-5-TR also introduced a related condition called social communication disorder. This diagnosis is used for people who have social communication challenges but do not show restricted or repetitive behaviors.

It’s unclear how social communication disorder relates to autism. Some health experts see overlap, while others consider it a separate condition.

Other Conditions That May Occur With Autism

The DSM recommends that people diagnosed with ASD be screened or evaluated for other related conditions, including:

• Genetic conditions known to be linked with autism
• Intellectual disabilities
• Language or communication delays
• Neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD)
• Mental health concerns like anxiety or depression
• Sleep difficulties

This helps create a more complete picture of each person’s strengths and support needs.

The 3 Levels of Autism Spectrum Disorder

In addition to diagnosing autism spectrum disorder, many healthcare providers also describe a person’s support needs using what the DSM-5-TR calls “severity specifiers.” These are not different types of autism — they’re used to describe how much support a person currently needs in two main areas:

• Social communication skills
• Restricted or repetitive behaviors

Someone might need more support in one area than the other. These levels can help guide services and therapies, but they can change over time and may not reflect everything a person experiences day to day.

1. ASD Level 1

Level 1 is considered the least intensive level of support on the autism spectrum, but that doesn’t mean support isn’t needed.

People at level 1 may be able to communicate using full sentences and participate in conversations, but they might find back-and-forth social interaction difficult without help. Making friends, adjusting to social cues, or understanding unspoken rules can be a challenge.

In terms of behavior, people at this level may struggle with changes in routine or transitions between activities, which can interfere with daily functioning. They may also engage in repetitive behaviors or have strong interests that may be highly focused or specific.

2. ASD Level 2

People diagnosed with level 2 autism usually need moderate or substantial support.

Socially, they may speak in short sentences or use limited language. Some may only talk about specific interests or may avoid interacting with others. Nonverbal communication — like facial expressions, gestures, or eye contact — may also be limited or different from what others expect.

In terms of behavior, people with level 2 ASD may have significant difficulty coping with change. They may become distressed when routines are disrupted or when asked to shift activities. Flexibility, problem-solving, and adjusting to others’ needs can be especially challenging.

3. ASD Level 3

People at level 3 need the highest level of support. Their differences in communication and behavior may have a major impact on everyday life, especially without consistent, individualized support.

Communication may be very limited or nonverbal. Some people may use only a few words, gestures, or assistive tools like speech-generating devices. Many may not initiate interaction or may respond only when prompted or when needing something.

Behaviorally, repetitive movements or routines may be especially intense and central to the person’s daily life. Changes or interruptions — even small ones — can lead to strong distress or emotional reactions.

Profiles of Autism: A Growing Area of Research

Some researchers are exploring profiles of autism — ways to describe patterns of traits within the autism spectrum. They argue that the current system, which uses a single ASD diagnosis and support levels, may not reflect the wide range of differences among autistic people.

People with very different strengths and challenges often receive the same diagnosis. Researchers say this can make it harder to provide personalized support. They also note that a person’s profile may change over time.

One study proposed up to 10 different profiles of autism. Other health experts consider traits like pathological demand avoidance as possible profiles. The goal is to move beyond a one-size-fits-all approach and tailor care to individual needs.

However, these profiles are not part of any official diagnosis, and there isn’t enough research yet to confirm how useful they are. For now, they may help people better understand their experiences — but they shouldn’t replace a full evaluation by a healthcare provider.

Does the Level of Support Model Work?

The levels of support model can be helpful for people diagnosed with autism, as well as their families, friends, educators, employers, peers, and healthcare providers. On the positive side, it recognizes that autism can look very different from person to person and that support needs can vary widely.

But the system isn’t perfect. Support levels can change over time, and the model doesn’t always give clear guidance about what kind of support a person needs day to day. It also doesn’t predict how a person’s strengths or challenges might change in the future. For example, someone might need more support with social interaction than with repetitive behaviors — or need different levels of support on different days.

All of this shows that the current system has limits. Just as the autism diagnosis changed in 2013 with the DSM-5, it may change again as research continues to evolve. In the meantime, talking with a knowledgeable healthcare provider can help you better understand what support options are available — and how the science of autism is changing.

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On MyAutismTeam, people share their experiences with autism, get advice, and find support from others who understand.

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