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What is the ICD Code for Autism?

September 22, 2023

When you have a child or children with autism, you probably spend more time with doctors and therapists than most other families. First, there’s the search for a diagnosis, then there are potential treatments, not to mention the other conditions—such as ADHD or gastrointestinal issues—sometimes associated with ASD. 

What is the ICD Code for Autism?

All this means you’ve almost certainly come into contact with the ICD-10-CM. What does this string of letters and numbers mean, and how does it connect to autism? In this article, we’ll explore the ICD and how it impacts autism diagnosis.

What is the ICD-10-CM index?

The ICD-10-CM index is a version of the International Classification of Diseases, a tool created by the World Health Organization. It’s essentially a list of diseases, disorders, and other health conditions, all of which are categorized and labeled with a code made up of letters and numbers. 

The ICD got its start as the International Statistical Institute’s International List of Causes of Death in 1893. Eventually, the World Health Organization took over its maintenance, and it was expanded to include all conditions, not just fatal ones. Every country that is a member of WHO must use the ICD to compile national death and disease statistics. 

Member countries currently use the tenth edition of the ICD, called ICD-10. The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) is a version created for use in the United States. The U.S. uses the ICD-10-CM to diagnose conditions and record patient information, and it uses the standard ICD-10 to classify data from death certificates.

ICD-10 came into effect globally in 1990, but the United States didn’t begin using it for mortality information until 1999 and didn’t fully transition to the ICD-10-CM until 2015. That’s why some websites will list what tenth revision codes are equivalent to those from its predecessor, the ICD-9—although there aren’t exact matches, since the transition to the tenth edition added about 55,000 new codes.

These codes have important purposes in the medical world. On a larger scale, public health officials use the data to conduct research and keep track of trends. For patients and caregivers, codes are usually used in hospital billing and insurance claims.

How is autism classified in the ICD-10-CM Index?

Autism is labeled with the code F84.0. It is a “billable code,” meaning it’s detailed enough to constitute a medical diagnosis. It falls under the section for mental and behavioral disorders (codes F00 through F99), the subsection of pervasive and specific developmental disorders (F80 through F89), and the smaller subsection of pervasive developmental disorders (F84). 

The ICD defines a pervasive developmental disorder as “severe distortions in the development of many basic psychological functions that are not normal for any stage in development.” F84 itself is a non-billable code, so it can’t be entered into any system as a diagnosis, but every code that falls under it (F84.0 through F84.9) can. 

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Looking at F84.0 autistic disorder

The description of F84.0 autistic disorder in the ICD is basically the same as other descriptions of autism—children with ASD will have difficulties with social interaction, language and communication skills, and repetitive behavior that become evident in early childhood, particularly before the age of three.  

An ICD code may have “inclusion terms,” which are other conditions the code can be used for. Often, the inclusion terms are just synonyms of the primary one. In the case of code F84.0, the inclusion terms are autism spectrum disorder, infantile autism, infantile psychosis, and Kanner’s syndrome. 

The ICD also has Type 1 Excludes Notes, which indicate when two codes should never be diagnosed alongside each other. In this case, autism and asperger’s syndrome are considered to be mutually exclusive (a position not taken by all diagnostic authorities, as we’ll see later). Asperger’s syndrome is called code F84.5 instead of code F84.0. The difference, according to the ICD, is that children with asperger’s don’t have the language and cognitive impairments that can be found in other autism spectrum disorders.

ICD coding allows professionals to include an additional code in their diagnosis, so they can further specify the disorder or identify any associated medical condition such as an intellectual disability. In that case, the patient would be coded for F84.0 autistic disorder as well as a code between F70-F79, which represent mild, moderate, severe, and unspecified intellectual disabilities.

Autism in the ICD-9

American children diagnosed with autism before 2015, when the ICD-9 phased out, may have received the code 299.0 or 299.1. Code 299.0 indicated “autistic disorder, current or active state” and 299.1 indicated “autistic disorder, residual state,” meaning the patient used to meet the criteria for an ASD diagnosis but no longer does. People with ASD in a residual state may still have symptoms found in autism, but not enough to maintain the diagnosis. Either way, both codes now fall under F84.0 autistic disorder.

The DSM V is the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, published by the American Psychiatric Association. It has been in effect since 2013. Unlike the ICD, it only covers mental conditions. But they have similar purposes in providing a shared, consistent set of terms and diagnostic criteria for health care professionals.

Because they’re created by two separate organizations, there are some discrepancies between the two manuals. For example, in the ICD-10, childhood disintegrative disorder, asperger’s syndrome, and pervasive developmental disorder-not otherwise specified each has its own code separate from autism. The American Psychiatric Association, however, collapsed each of these diagnoses under autism spectrum disorder.

That said, the indexes have very similar definitions of ASD. Both emphasize repetitive behavior, struggles with social interaction and communication, and the appearance of symptoms in early childhood. 

The main difference between the two is that DSM-V codes can not be submitted for insurance claims. They are only useful for identification and diagnosis. If an insurance claim is submitted in the United States without an ICD code, it will be rejected.


Clearly, the ICD-10-CM is important for anyone with long-term medical diagnoses. As research is done and advances are made, the ICD will continue to change how we understand and classify conditions.

In fact, the ICD-11 is already on its way—WHO member countries will be allowed to implement it in 2022, though the United States isn’t expected to fully adopt it until the latter end of the decade. 

Autism has a new code in the ICD-11: 6A02, now called “autism spectrum disorder” instead of “autistic disorder”. There is a new range of codes from 6A02.0 to 6A02.5, indicating whether the individual has impaired intellectual development or functional language. ICD-11 has also followed the DSM-V’s lead in including asperger’s syndrome under ASD. 

We don’t know when ICD-11 will reach the U.S., or what, if any, modifications will be made to it. Either way, this article has hopefully helped you understand its purpose. Whether ASD is known as code F84.0, 6A02, 299.0, or something else in the future, autistic people and their loved ones represent a vibrant, supportive community.


Autism Speaks. (n.d.). DSM-5 and Autism: Frequently Asked Questions. Autism Speaks. https://www.autismspeaks.org/dsm-5-and-autism-frequently-asked-questions

Bielby, J. (2020, May 4). ICD-10, ICD-10-CM, & ICD-10-PCS. A.R. Dykes. https://guides.library.kumc.edu/icd10

Boyd, N. (n.d.). Diagnostic Codes: DSM-5 vs ICD-10. KASA. https://kasa-solutions.com/diagnostic-codes-dsm-5-vs-icd-10/

Holman, T. (2018, October). ICD-10-CM (Clinical Modification). TechTarget. https://searchhealthit.techtarget.com/definition/ICD-10-CM

World Health Organization. (2021). International Statistical Classification of Diseases and Related Health Problems (ICD). World Health Organization. https://www.who.int/standards/classifications/classification-of-diseases

World Health Organization. (2021). 2021 ICD-10-CM CODE F84.0. ICD List. https://icdlist.com/icd-10/F84.0

World Health Organization. (2021, May). 6A02 Autism spectrum disorder. ICD-11 for Mortality and Morbidity Statistics. https://icd.who.int/browse11/l-m/en#/http%3a%2f%2fid.who.int%2ficd%2fentity%2f437815624

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