They’re the same thing. ASD — Autism Spectrum Disorder — is the formal diagnostic term you’ll see in medical records and evaluation reports. Autism is the everyday term most people use in conversation. There is no medical distinction between them, and neither one is more accurate than the other.
If you’ve been seeing both terms and wondering whether they mean something different, they don’t. Here’s a bit more context on where each term comes from and what they actually mean.
Why Two Terms Exist
Before 2013, the diagnostic landscape looked quite different. Clinicians used several separate diagnoses to describe what we now call autism (e.g., Autistic Disorder, Asperger’s Syndrome, Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS), and Childhood Disintegrative Disorder, among others).
In 2013, the DSM-5 — the manual clinicians use to diagnose mental and developmental conditions — merged all of these into a single umbrella diagnosis: Autism Spectrum Disorder. This wasn’t a change in what autism is, but rather a change in how it’s classified. The goal was to reflect that autism exists on a spectrum with varying presentations and needs, rather than as separate, disconnected conditions.
The word “autism” has been around much longer than ASD as a formal term, which is why it stuck in everyday language even as the clinical terminology shifted.
What Does “Spectrum” Mean?
The word spectrum doesn’t mean a straight line from mild to severe. It reflects the fact that autism presents very differently from one person to the next. Two children with the same ASD diagnosis can have vastly different strengths, challenges, and support needs. One might be highly verbal with strong academic skills but struggle significantly in social situations. Another might have limited spoken language and need support with most daily living tasks. Both are autistic.
To capture this range, the DSM-5 uses three support levels to describe how much assistance an individual needs in daily life.
The Three Levels of Autism
Level 1 is described as “requiring support.” People at this level can generally function independently in many areas but need some help with social communication and managing transitions or changes in routine.
Level 2 is “requiring substantial support.” Individuals at this level have more noticeable challenges with communication and behavior, and need more consistent help across different settings.
Level 3 is “requiring very substantial support.” This level reflects significant challenges in communication and daily functioning, with a greater need for assistance throughout the day.
These levels describe support needs — they don’t define a person’s potential or place a ceiling on what they can achieve.
Terms You May Still Hear
Even though the DSM-5 consolidated autism into a single diagnosis over a decade ago, older terms still show up — in school records, from family members, or in resources that haven’t been updated. Here are some terms you may still hear and what they mean:
Asperger’s Syndrome
Asperger’s Syndrome is no longer a standalone diagnosis. Since 2013, individuals who would previously have received this diagnosis are now diagnosed with ASD, typically at Level 1. Some people who were diagnosed with Asperger’s before the change still identify with the term, and that’s a personal choice worth respecting.
PDD-NOS
PDD-NOS stood for Pervasive Developmental Disorder – Not Otherwise Specified. It was used when someone showed some characteristics of autism but didn’t meet the full criteria for a more specific diagnosis. Like Asperger’s, it’s been folded into ASD.
“High-Functioning” and “Low-Functioning”
These terms aren’t clinical (you won’t find them in the DSM-5) and most clinicians and autism advocates have moved away from using them. The problem is that they oversimplify. Describing someone as “high-functioning” can cause real support needs to be overlooked. Describing someone as “low-functioning” can obscure their strengths. The support level system (1, 2, 3) is a more accurate and useful way to describe where a person needs help.
A Note on Language
Within the autism community, people have genuine and differing preferences about how to talk about autism. Some prefer identity-first language (e.g., “autistic person”) because they see autism as an integral part of who they are. Others prefer person-first language (e.g., “person with autism”) — because they want to lead with the person rather than the diagnosis. Both are valid, and neither is wrong. When in doubt, follow the lead of the individual or family you’re talking with.
What This Means for Your Family
Whether your child’s evaluation report says “Autism Spectrum Disorder,” a teacher says “autism,” or an older relative mentions Asperger’s, they’re all referring to the same diagnosis. The terminology doesn’t change your child’s needs, their strengths, or their eligibility for support services.
What matters is understanding your child as an individual and connecting with the right help. If you’d like to learn more about what ABA therapy looks like for children across the spectrum, you can read more about what ABA therapy is or browse our ABA parent resources.
Frequently Asked Questions
Is ASD the same as autism?
Yes. ASD (Autism Spectrum Disorder) is the formal clinical term, and autism is the commonly used everyday term. They refer to the same diagnosis.
What does ASD stand for?
ASD stands for Autism Spectrum Disorder. It’s the official diagnostic term used in the DSM-5, the manual clinicians use to diagnose developmental and mental health conditions.
Is Asperger’s still a diagnosis?
No. Asperger’s Syndrome was removed as a separate diagnosis in 2013 when the DSM-5 was published. It’s now part of the broader ASD diagnosis, generally at Level 1. Some people who received that diagnosis before 2013 still identify with the term.
What are the 3 levels of autism?
The DSM-5 describes three support levels: Level 1 (requiring support), Level 2 (requiring substantial support), and Level 3 (requiring very substantial support). The levels describe how much help a person needs in daily life, not their potential or abilities.
Does the term used affect my child’s services or eligibility?
No. Whether a record says ASD or autism, it’s the same diagnosis and carries the same eligibility for services, therapy, and school-based support.
