2026 ICD-10-CM Diagnosis Code K00.4Disturbances in tooth formation

ICD-10-CM CodesK00–K95K00-K14K00

ICD-10-CM K00.4
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

K00.4 is a billable ICD-10-CM diagnosis code for disturbances in tooth formation. 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
K00.4
Billable Status
Yes — Valid for Submission
Code Describes
Disturbances in tooth formation
Short Description
Disturbances in tooth formation
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 CodeK00.4Disturbances in tooth formation

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Agenesis of enamel
  • Amelocerebrohypohidrotic syndrome
  • Antenatal enamel hypoplasia
  • Aplasia of cementum
  • Arrest of growth of root of tooth due to and following dental trauma
  • Blepharophimosis, intellectual disability syndrome
  • Deafness, enamel hypoplasia, nail defect syndrome
  • Dental caries associated with enamel hypomineralization
  • Dental caries associated with enamel hypoplasia
  • Dental caries secondary to developmental defects of tooth structure
  • Developmental anomaly of crown and root formation
  • Dilaceration of crown of permanent tooth due to and following dental trauma
  • Dilaceration of tooth
  • Divergence of root of tooth
  • Dysplasia of cementum
  • Enamel dysplasia
  • Enamel hypoplasia
  • Generalized enamel hypomineralization
  • Generalized enamel hypoplasia associated with ingestion of drugs
  • Generalized enamel hypoplasia associated with radiation therapy
  • Generalized enamel hypoplasia associated with systemic disease
  • Generalized enamel hypoplasia of undetermined etiology
  • Hypocalcification of teeth
  • Hypohidrosis
  • Hypohidrosis, enamel hypoplasia, palmoplantar keratoderma, intellectual disability syndrome
  • Hypomineralization of enamel of molar tooth
  • Hypomineralization of enamel of second primary molar tooth
  • Hypomineralization of enamel of teeth
  • Hypomineralization of enamel of tooth
  • Hypomineralization of tooth
  • Hypoplasia of cementum
  • Hypoplasia of enamel due to congenital syphilis
  • Hypoplasia of tooth
  • Hypoplastic enamel-onycholysis-hypohidrosis syndrome
  • Intellectual disability, congenital heart disease, blepharophimosis, blepharoptosis and hypoplastic teeth
  • Localized enamel hypomineralization associated with localized infection
  • Localized enamel hypomineralization associated with localized trauma
  • Localized enamel hypomineralization of undetermined etiology
  • Localized enamel hypoplasia
  • Localized enamel hypoplasia associated with local infection
  • Localized enamel hypoplasia associated with localized trauma
  • Localized enamel hypoplasia of undetermined etiology
  • Molar incisor hypomineralization
  • Neonatal enamel hypoplasia
  • Partial arrest of growth of root of tooth due to and following dental trauma
  • Regional odontodysplasia
  • Root angulation of tooth
  • Secondary dental caries associated with local or systemic factors
  • Short stature, unique facies, enamel hypoplasia, progressive joint stiffness, high-pitched voice syndrome
  • Turner's tooth
  • Vestibular root angulation of tooth
  • XTE syndrome

Tabular List NotesGuidance

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

Inclusion Terms

  • Aplasia and hypoplasia of cementum
  • Dilaceration of tooth
  • Enamel hypoplasia (neonatal) (postnatal) (prenatal)
  • Regional odontodysplasia
  • Turner's tooth

Type 1 Excludes

  • Hutchinson's teeth and mulberry molars in congenital syphilis A50.5

Type 2 Excludes

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.

    • Amelogenesis imperfecta
      • nonhereditaria (segmentalis)
    • Aplasia
      • cementum
    • Calcification
      • dentinal papilla
    • Dilaceration, tooth
    • Disturbance(s)
      • tooth
        • formation
    • Ghost
      • teeth
    • Hypoplasia, hypoplastic
      • cementum
    • Hypoplasia, hypoplastic
      • enamel of teeth (neonatal) (postnatal) (prenatal)
    • Hypoplasia, hypoplastic
      • Turner's
    • Odontodysplasia, regional
    • Pitting
      • teeth
    • Turner's
      • hypoplasia (tooth)
    • Turner's
      • 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

  • Hypohidrosis

    abnormally diminished or absent perspiration. both generalized and segmented (reduced or absent sweating in circumscribed locations) forms of the disease are usually associated with other underlying conditions.
  • Grade 2 Hypohidrosis, CTCAE|Grade 2 Hypohidrosis

    symptomatic; limiting instrumental adl or mild/moderate impact on age-appropriate normal daily activity (pediatric)
  • Grade 3 Hypohidrosis, CTCAE|Grade 3 Hypohidrosis

    increase in body temperature; limiting self-care adl or severe impact on age-appropriate normal daily activity (pediatric)
  • Grade 4 Hypohidrosis, CTCAE|Grade 4 Hypohidrosis

    life-threatening consequences; urgent intervention indicated
  • Enamel Hypoplasia

    deficiency in the enamel tissue that results in the formation of grooves, pits, or dents on the surface of the affected teeth.
  • Grade 2 Hypohidrosis, CTCAE|Grade 2 Hypohidrosis

    symptomatic; limiting instrumental adl
  • Grade 3 Hypohidrosis, CTCAE|Grade 3 Hypohidrosis

    increase in body temperature; limiting self care adl
  • Grade 4 Hypohidrosis, CTCAE|Grade 4 Hypohidrosis

    heat stroke
  • Grade 5 Hypohidrosis, CTCAE|Grade 5 Hypohidrosis

    death
  • Hypohidrosis

    reduced sweating. causes include burns, dehydration, radiation, and leprosy.
  • Hypohidrosis, CTCAE|Hypohidrosis|Hypohidrosis

    a disorder characterized by reduced sweating.

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 K00.4 to ICD-9-CMHistory

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

ICD-9-CM
520.4 Tooth formation disturb
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 K00.4Overview

Is K00.4 (Disorders of tooth development and eruption) a billable code?

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

What MS-DRG does K00.4 group to?

When disturbances in tooth formation 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 K00.4?

Under the General Equivalence Mappings, disturbances in tooth formation converts to ICD-9-CM 520.4 (tooth formation disturb). 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.