Autism
Types of Autism: What Replaced the Old Categories
There are no longer official types — what replaced them, and the ways autistic people genuinely do differ.
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There are no longer separate types of autism. Until 2013, the DSM-IV listed several distinct conditions — autistic disorder, Asperger's syndrome, PDD-NOS, and childhood disintegrative disorder — and the DSM-5 merged all four into a single diagnosis of autism spectrum disorder. ICD-11 made the same change effective 2022. The reason was practical: clinicians could not reliably tell the categories apart, so the same person might receive different labels depending on who assessed them. Instead of types, both systems now describe individual profiles — the DSM-5 using three levels of support need, and ICD-11 using separate specifiers for intellectual functioning and language ability. Diagnoses given under the old system remain valid and do not expire.
Why you're probably here
Most people land on this page because someone — a clinician, a school, a relative — used one of the old terms: Asperger's, PDD-NOS, classic or Kanner's autism, atypical autism, high- or low-functioning autism. Each of those has its own page explaining what it meant and where it fits now.
If you were given one of these terms, here's where it fits now:
Asperger's syndrome · PDD-NOS · Childhood disintegrative disorder · Classic (Kanner's) autism · Atypical autism · Low-functioning autism · High-functioning autism
What changed in 2013 and 2022
Until 2013, the DSM-IV divided autism into several separate conditions. The DSM-5 (published May 2013) merged four of them1 — autistic disorder, Asperger's syndrome, PDD-NOS, and childhood disintegrative disorder — into the single diagnosis of autism spectrum disorder. ICD-11, the World Health Organization's system, made the same move, effective January 2022.3
One condition was handled differently: Rett syndrome was removed from the autism category entirely, not merged, because it is a distinct genetic condition. Existing autism diagnoses given under the old system remain valid.
Why the categories were retired
Three reasons, and they reinforce each other:
- They were unreliable in practice. Clinicians could not consistently tell the categories apart, so the same child might be called autistic by one assessor and given Asperger's or PDD-NOS by another.
- The genetic model didn't hold. Hundreds of genes are associated with autism, and none map cleanly onto any one subtype.
- There was a service gap. Some states and systems funded support for "autism" but not for "Asperger's," so a label could decide whether a child got help.
What replaced them
DSM-5 support levels (1–3). Instead of types, the DSM-5 describes how much support a person needs — with the honest caveat that needs vary by situation and change over time. A level is a description of current support needs, not a fixed trait.
ICD-11 specifiers. ICD-11 keeps two things separate that the levels blend together: intellectual functioning and language ability, each noted independently. Many people find this more useful, because a person can have significant language differences and no intellectual disability, or the reverse.
The way autistic people actually differ
This is the useful part. Autistic people differ enormously — but along dimensions, not types: sensory processing, communication style, attention, support needs that shift across settings, and how much a person masks. Several of these have their own pages:
Where sensory processing fits
The DSM-5 added sensory hyper- and hyporeactivity to the autism criteria in 2013 and ICD-11 followed in 2022, so both current manuals now include sensory features. The practical consequence: anyone assessed under an older framework almost certainly never had their sensory processing evaluated, even though it is often central to daily life. See sensory processing and autism and sensory processing differences.
What autism is, how it's diagnosed, and how autistic people describe their own experience.
Read the autism overview →Frequently Asked Questions
What are the types of autism?
There are no longer separate types. Since the DSM-5 in 2013 (and ICD-11 in 2022), autism is diagnosed as one condition — autism spectrum disorder — that describes a wide range of individual profiles rather than distinct categories.
Is Asperger's a type of autism?
Asperger's is not a current diagnosis. It was one of the categories merged into autism spectrum disorder in 2013, and it is not a standalone diagnosis in ICD-11. People diagnosed with Asperger's before the change are autistic; the diagnosis remains valid.
Is there a mild form of autism?
"Mild autism" isn't a category. What people usually mean is lower support needs in the areas other people can see — which frequently coexists with substantial hidden cost, such as the effort of masking. See high-functioning autism.
Does my old diagnosis still count?
Yes. A diagnosis given under the old system remains valid and does not expire. You do not need to be re-diagnosed because the categories changed.
What are autism levels 1, 2, and 3?
The DSM-5 uses three levels to describe how much support a person needs in social communication and in restricted/repetitive behaviors. They describe current support needs, not fixed traits — needs vary by situation and change over time.
What's the difference between autism and autism spectrum disorder?
They refer to the same thing. "Autism spectrum disorder" is the current diagnostic term; "autism" is the everyday word for it.
Sources
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). APA Publishing; May 2013.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). APA Publishing; 2022.
- World Health Organization. ICD-11 for Mortality and Morbidity Statistics, 6A02 Autism spectrum disorder. Effective January 2022. Checked August 18, 2026.
Medical disclaimer. This page is for general educational purposes and does not constitute medical advice, diagnosis, or treatment. If your child has lost skills they previously had, contact their doctor promptly.