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  6. 2026 ICD-10-CM Code K00.9

2026 ICD-10-CM Diagnosis Code K00.9

Disorder of tooth development, unspecified

ICD-10-CM Code:
K00.9
ICD-10 Code for:
Disorder of tooth development, unspecified
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

K00.9 is a billable diagnosis code used to specify a medical diagnosis of disorder of tooth development, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Unspecified diagnosis codes like K00.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Code Classification

  • Diseases of the digestive system
    K00–K95
    • Diseases of oral cavity and salivary glands
      K00-K14
      • Disorders of tooth development and eruption
        K00

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • CODAS syndrome
  • Congenital anomaly of tooth
  • Developmental abnormality of canine tooth
  • Developmental abnormality of deciduous tooth
  • Developmental abnormality of incisor tooth
  • Developmental abnormality of molar tooth
  • Developmental abnormality of premolar tooth
  • Disorder of tooth development
  • Enamel spur
  • Malformation of teeth
  • Malformation of tooth
  • Melanin pigmentation of oral mucosa
  • Melanosis of mucosa of body orifice
  • Nail and tooth abnormalities, marginal palmoplantar keratoderma, oral hyperpigmentation syndrome
  • Oligodontia
  • Spondyloepimetaphyseal dysplasia, abnormal dentition syndrome
  • Uncombable hair, retinal pigmentary dystrophy, dental anomaly and brachydactyly syndrome

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Any dental condition including traumatic injury

CCSR Code: DEN001

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Disorders of teeth and gingiva

CCSR Code: DIG002

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Nontraumatic dental conditions

CCSR Code: DEN002

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Clinical Information

  • Codas Syndrome

    a rare syndrome caused by mutations in the lonp1 gene. it is characterized by developmental delay, cerebral, ocular, dental, auricular, and skeletal abnormalities.

  • AXIN2-Associated Polyposis|ODCRCS|Oligodontia-Colorectal Cancer Syndrome

    a rare autosomal dominant syndrome caused by constitutional (germline) loss-of-function variants in axin2 gene. it is characterized by the presence of multiple colorectal adenomatous polyps and an increased risk of colorectal carcinoma. oligodontia and ectodermal dysplasia may or may not be present.

  • EDA wt Allele|ECTD1|ED1|ED1-A1|ED1-A2|EDA|EDA-A1|EDA-A2|EDA1|EDA2|Ectodermal Dysplasia 1, Anhidrotic Gene|Ectodysplasin A wt Allele|Ectodysplasin Gene|HED|HED1|ODT1|Oligodontia 1 Gene|STHAGX1|TNLG7C|XHED|XLHED

    human eda wild-type allele is located in the vicinity of xq13.1 and is approximately 423 kb in length. this allele, which encodes ectodysplasin-a protein, is involved in the morphogenesis of ectodermally derived tissues. mutation of the gene is associated with x-linked hypohidrotic ectodermal dysplasia type 1 and x-linked, selective tooth agenesis type 1.

  • Oligodontia

    the congenital absence of six or more permanent teeth with the exclusion of third molars.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Disorder of odontogenesis NOS

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Anomaly, anomalous(congenital) (unspecified type)
      • tooth, teeth
    • Disorder(of)
      • odontogenesis NOS
    • Disorder(of)
      • tooth
        • development
    • Malformation(congenital)
      • teeth, tooth

Convert K00.9 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Tooth devel/erup dis NOS

ICD-9-CM: 520.9

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

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Patient Education


Tooth Disorders

What are teeth?

Your teeth are made of a hard, bonelike material. There are four parts:

  • Enamel, your tooth's hard surface
  • Dentin, the hard yellow part under the enamel
  • Cementum, the hard tissue that covers the root and keeps your teeth in place
  • Pulp, the soft connective tissue in the center of your tooth. It contains nerves and blood vessels.

You need your teeth for many activities that you may take for granted. These include eating, speaking and even smiling.

What are tooth disorders?

There are many different problems that can affect your teeth, including:

  • Tooth decay - damage to a tooth's surface, which can lead to cavities
  • Abscess - a pocket of pus, caused by a tooth infection
  • Impacted tooth - a tooth that did not erupt (break through the gum) when it should have. It is usually wisdom teeth that are impacted, but it can sometimes happen to other teeth.
  • Misaligned teeth (malocclusion)
  • Tooth injuries such as broken or chipped teeth

What causes tooth disorders?

The causes of tooth disorders varies, depending on the problem. Sometimes the cause is not taking good care of your teeth. In other cases, you may have been born with the problem or the cause is an accident.

What are the symptoms of tooth disorders?

The symptoms can vary, depending on the problem. Some of the more common symptoms include:

  • Abnormal color or shape of the tooth
  • Tooth pain
  • Worn-down teeth

How are tooth disorders diagnosed?

Your dentist will ask about your symptoms, look at your teeth, and probe them with dental instruments. In some cases, you may need dental x-rays.

What are the treatments for tooth disorders?

The treatment will depend on the problem. Some common treatments are:

  • Fillings for cavities
  • Root canals for cavities or infections that affect the pulp (inside of the tooth)
  • Extractions (pulling teeth) for teeth that are impacted and causing problems or are too damaged to be fixed. You may also have a tooth or teeth pulled because of overcrowding in your mouth.

Can tooth disorders be prevented?

The main thing that you can do to prevent tooth disorders is to take good care of your teeth:

  • Brush your teeth twice a day with a fluoride toothpaste
  • Clean between your teeth every day with floss or another type of between-the-teeth cleaner
  • Limit sugary snacks and drinks
  • Don't smoke or chew tobacco
  • See your dentist or oral health professional regularly

[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.