Types of Autism: The Old Five-Category System and What It Maps to Today
The "5 types of autism" framework was retired in 2013. Here's what those terms now map to under the DSM-5-TR, and what the three current levels mean.
Types of Autism: The Old Five-Category System and What It Maps to Today
Types of Autism: The Old Five-Category System and What It Maps to Today
Here's something that trips up a lot of parents: the "five types of autism" — classic autism, Asperger's syndrome, PDD-NOS, childhood disintegrative disorder, and Rett syndrome — describe a diagnostic framework that was retired in 2013. They're not how autism is diagnosed today.
The direct answer: Under the current DSM-5-TR (updated 2022), there is one diagnosis — autism spectrum disorder (ASD) — with three severity levels based on how much support a person needs. The old five-category system has been replaced. Three of the original categories became ASD Levels 1, 2, and 3. The other two are no longer classified as autism at all.
This guide walks through what each of the historical terms meant, where they land in today's framework, and what the three current levels actually describe — so whether you're reading an old diagnosis, helping a family member understand their record, or trying to make sense of a recent evaluation, you have a clear translation.
The Current Framework: One Diagnosis, Three Levels
Under the DSM-5-TR — the diagnostic manual used by U.S. clinicians, last revised in 2022 — there is one autism diagnosis: autism spectrum disorder. To receive it, a person must show persistent differences in two core domains:
- Social communication and social interaction
- Restricted or repetitive patterns of behavior, interests, or activities
Within that single diagnosis, the clinician specifies a severity level based on how much support the person currently needs in each domain.
Two things matter here that clinicians sometimes don't explain clearly:
Levels describe current support needs, not permanent traits. A level can shift with age, intervention, environment, and life circumstances. It's a snapshot of where someone is right now — not a permanent ceiling.
The two domains are rated separately. A person can be Level 1 for social communication and Level 2 for restricted/repetitive behaviors, or any other combination. The overall level in the report is usually a summary, not a single fixed number for both areas.
The DSM-5-TR also requires clinicians to note whether the diagnosis is accompanied by intellectual impairment, language impairment, a known medical or genetic condition, another neurodevelopmental or mental health condition, or catatonia. These specifiers give a much fuller picture than a single label alone.
📌 Just received a diagnosis — or trying to make sense of one? Understanding what a diagnosis means for services is a separate step from the diagnosis itself. Apex ABA's BCBA team works with families in North Carolina, Georgia, and Maryland to explain what a specific evaluation report means for ABA therapy, what insurance typically covers, and whether ABA is the right fit for your child (ages 2–12). No commitment required for the first conversation. Talk to an Apex BCBA about next steps →
Translating the Old "Types of Autism" Into Current Language
Most parents searching for "types of autism" have encountered the older terms somewhere — in a relative's medical record, an older book, a school file from the early 2000s, or a conversation with someone who was diagnosed before 2013. Here's what each category referred to, and where it sits in today's framework.
1. Classic Autism (Autistic Disorder)
Under the DSM-IV, "autistic disorder" required marked differences in social interaction, communication, and restricted/repetitive behaviors, with onset before age 3. The name "classic autism" was informal — the clinical term was autistic disorder, sometimes called Kanner's autism after Leo Kanner, the psychiatrist who first described the pattern in 1943.
Today: A person who would have received this diagnosis is now diagnosed with autism spectrum disorder, typically Level 2 or Level 3, depending on current support needs. The diagnosis itself doesn't change — the label does.
2. Asperger's Syndrome
Asperger's was a DSM-IV category for people with autism-like social differences who had age-appropriate language development and average or above-average intelligence. The category was applied inconsistently — clinicians frequently disagreed about where Asperger's ended and what was then called "high-functioning autism."
Today: A person who would have received an Asperger's diagnosis is now evaluated and typically diagnosed with autism spectrum disorder, Level 1. The DSM-5-TR explicitly states that individuals with a well-established prior diagnosis of Asperger's disorder qualify for the current ASD diagnosis.
Adults who received an Asperger's diagnosis before 2013 still hold that diagnosis. Many continue to use the term — for legitimate reasons, including community identity and personal history. That's not wrong. It just reflects when the diagnosis was issued, not a different condition.
3. Pervasive Developmental Disorder — Not Otherwise Specified (PDD-NOS)
PDD-NOS was the catch-all DSM-IV category for people who showed clear autism-like differences but didn't fit cleanly into autistic disorder or Asperger's. It was applied broadly — sometimes for milder presentations, sometimes for atypical ones.
Today: Most people who would have received a PDD-NOS diagnosis are now evaluated under autism spectrum disorder, Level 1 or Level 2. A smaller group — particularly those whose primary challenges were in social communication without clear restricted/repetitive behaviors — may instead receive a diagnosis of social (pragmatic) communication disorder, a separate DSM-5-TR category.
4. Childhood Disintegrative Disorder (CDD)
Also called Heller's syndrome, CDD described children who developed typically through age 2 or later and then experienced a significant regression in language, social skills, and other previously acquired abilities. It was rare — population estimates placed prevalence around 2 per 100,000 children.
Today: Childhood disintegrative disorder is no longer a separate diagnosis. Cases that would previously have been labeled CDD now fall under autism spectrum disorder, with the developmental regression documented in the history and captured through available DSM-5-TR specifiers rather than a separate category.
5. Rett Syndrome
Rett syndrome was grouped with autism in the DSM-IV because of overlapping features in early childhood — social withdrawal, loss of purposeful movements, and developmental regression. It's a distinct genetic condition: in approximately 90–95% of cases, it's caused by mutations in the MECP2 gene on the X chromosome. It primarily affects females, and the clinical course — including specific patterns of hand movement loss and breathing irregularities — is quite different from autism.
Today: Rett syndrome is not classified as autism. The DSM-5 removed it from the autism category in 2013 based on genetic and clinical evidence that it's a different condition with different underlying mechanisms and different support needs. A person with Rett syndrome does not receive an autism diagnosis on the basis of Rett alone.
That said, some children with Rett syndrome are initially diagnosed with autism before the MECP2 mutation is identified — at which point the diagnosis is typically revisited.
Why the Framework Changed
The DSM-5 reorganization wasn't a cosmetic rename. Three things drove it, and they're documented in the research literature:
Diagnostic inconsistency. Multiple studies found that the same child could receive different diagnoses — autistic disorder, Asperger's, or PDD-NOS — from different clinicians looking at identical presentations. The category boundaries simply weren't reliable in practice.
Poor predictive value for support. The old labels didn't map well onto what kind of support a person actually needed. Two children with the same PDD-NOS diagnosis could have very different daily requirements. The level-based system — built around support needs rather than subtype — turned out to be more functionally useful.
Evidence for a genuine spectrum. Research in the decade leading up to DSM-5 consistently showed that autism is dimensional rather than categorical. Variation exists along a continuum, and labels like "high-functioning" and "low-functioning" obscured that — a person can have strong verbal skills and significant sensory or emotional regulation needs at the same time.
The current system has its critics. Some autistic adults feel the level system flattens individual complexity. Some clinicians consider Level 1 to be under-applied to people whose actual support needs are higher than the label implies. On balance, though, the field's consensus is that the DSM-5 framework is more accurate and more clinically useful than the five-type model it replaced.
Terms You'll Still See — and What They Mean
Some labels appear online, in community spaces, or in older records that don't map neatly onto DSM-5-TR categories. A brief guide:
"High-functioning autism" — Not a DSM-5-TR term. It's an informal way of describing what is now typically Level 1 ASD. Most autism researchers and many autistic people consider the term misleading, since it tends to mean "appears independent in casual settings" without capturing sensory, emotional, or executive functioning challenges that may be significant. The preferred framing is to describe specific strengths and specific support needs.
"High-masking autism" — Not a formal diagnostic category, but it describes a documented pattern: autistic people (often women, often diagnosed later in life) who consciously hide autistic traits in social settings. It's a clinically useful concept even without DSM-5-TR status. For more on how this shows up in adults, see our guide on signs of autism in adult men.
"PDA profile" (pathological demand avoidance) — Recognized in some U.K. clinical settings; not currently part of the DSM-5-TR. Research is ongoing.
"Autistic burnout" — Describes the exhaustion that can accumulate from sustained masking and chronic sensory overload. Not a separate diagnosis, but increasingly recognized clinically.
What to Do at the Beginning of This Process
If you're reading this because of concerns about a child:
Start with your pediatrician. The American Academy of Pediatrics recommends autism-specific screening at 18- and 24-month well-child visits. You can request it at any visit.
Know what a full evaluation includes. Most comprehensive evaluations combine developmental history, parent interview, direct observation (often the ADOS-2), and sometimes language, cognitive, or adaptive testing. For a detailed breakdown, see our parent's guide to ADOS testing.
Early intervention doesn't require a formal autism diagnosis to begin. If your child has documented developmental delays, you can access early intervention services through your state's IDEA Part C program before a diagnosis is finalized.
Conclusion: The Label Has Changed. The Support Need Hasn't.
Whether you're working from an older diagnosis that says "Asperger's" or a new evaluation that says "ASD Level 1," the practical question is the same: what does this child need, and where can they get it?
The DSM-5-TR gave clinicians a more consistent framework for answering that. But the framework itself doesn't provide support — it just names the starting point.
Apex ABA works with families from that starting point forward. If your child has an autism diagnosis and you're in North Carolina, Georgia, or Maryland, our BCBA team can explain what the specific level and specifiers in your child's report mean for ABA therapy, help verify your insurance coverage, and build an individualized program around your child's actual goals — in your home, in their school, or both.
The evaluation is just step one. See what comes next with Apex ABA →
Sources
- https://www.autism.org.uk/advice-and-guidance/topics/behaviour/stimming/all-audiences
- https://www.autismspeaks.org/autism-diagnostic-criteria-dsm-5
- https://my.clevelandclinic.org/health/articles/24291-diagnostic-and-statistical-manual-dsm-5
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11651641/
- https://pubmed.ncbi.nlm.nih.gov/11411788/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10217468/
- https://www.research.chop.edu/car-autism-roadmap/diagnostic-criteria-for-autism-spectrum-disorder-in-the-dsm-5
- https://www.medicalnewstoday.com/articles/childhood-disintegrative-disorder
- https://www.ncbi.nlm.nih.gov/books/NBK482252/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10886956/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC8531066/
Frequently Asked Questions
Is Asperger's syndrome still a valid diagnosis?
Not for new diagnoses in the U.S. The DSM-5 (2013) folded Asperger's, autistic disorder, and PDD-NOS into a single autism spectrum disorder diagnosis. Adults diagnosed before 2013 still hold that diagnosis and many use the term for personal and community identity reasons. The terminology change applies to new diagnoses — not retroactively.
What is "high-functioning" autism?
It's not a DSM-5-TR term. Clinicians today use Level 1 to describe autism with lower support needs. Most autism researchers and many autistic people consider "high-functioning" misleading because it tends to mean "presents well in casual settings" — which doesn't capture sensory, executive functioning, or masking-related challenges that may be substantial.
Is Rett syndrome autism?
No, not under the current DSM-5-TR. Rett syndrome was historically grouped with autism due to overlapping early features, but it's a distinct genetic condition caused primarily by mutations in the MECP2 gene. The DSM-5 separated it from autism in 2013 based on the genetic and clinical evidence.
My child's old report says "PDD-NOS." Does that diagnosis still count?
Yes. A diagnosis issued under DSM-IV criteria remains a valid medical record. Schools, insurers, and service providers generally accept older diagnoses. If you want updated DSM-5-TR terminology — for a specific service or for clarity — a clinician can reassess and issue a current diagnosis.
How do I find out what level my child has been assigned?
The severity level should be specified in the diagnostic report. If it isn't — which happens — ask the evaluating clinician directly. Some clinicians describe support needs in narrative form rather than assigning a numbered level, which is also acceptable under the DSM-5-TR.
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