2026 ICD-10-CM Diagnosis Code K00.9Disorder of tooth development, unspecified

ICD-10-CM CodesK00–K95K00-K14K00

ICD-10-CM K00.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K00.9 is a billable ICD-10-CM diagnosis code for disorder of tooth development, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 157 through 159. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury, Disorders of teeth and gingiva, and Nontraumatic dental conditions.

Code Identity

ICD-10-CM Code
K00.9
Billable Status
Yes — Valid for Submission
Code Describes
Disorder of tooth development, unspecified
Short Description
Disorder of tooth development, unspecified
Same as the full description in the CMS dataset.
Parent Code
Disorders of tooth development and eruption

Code Classification

ChapterK00–K95Diseases of the digestive system
SectionK00-K14Diseases of oral cavity and salivary glands
CategoryK00Disorders of tooth development and eruption
This CodeK00.9Disorder of tooth development, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • 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

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Disorder of odontogenesis NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this 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

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR DEN001
Any dental condition including traumatic injury
Default principal diagnosis: inpatient No · outpatient No
CCSR DIG002
Disorders of teeth and gingiva
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR DEN002
Nontraumatic dental conditions
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • 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.

Patient EducationClinical

Tooth Disorders

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

The full article covers:

  • What are teeth?
  • What are tooth disorders?
  • What causes tooth disorders?
  • What are the symptoms of tooth disorders?
  • How are tooth disorders diagnosed?
  • What are the treatments for tooth disorders?
  • Can tooth disorders be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert K00.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
520.9 Tooth devel/erup dis NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About K00.9Overview

Is K00.9 (Disorders of tooth development and eruption) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report disorder of tooth development, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does K00.9 group to?

When disorder of tooth development, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 157, 158, 159, with relative weights from 0.7085 to 1.7168 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of K00.9?

Under the General Equivalence Mappings, disorder of tooth development, unspecified converts to ICD-9-CM 520.9 (tooth devel/erup dis NOS). The mapping is a direct match.

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.