ICD-10 Code K00.1: Supernumerary teeth billing guide

Key Takeaways

ICD-10 Code K00.1 is a billable ICD-10-CM diagnosis code for supernumerary teeth, valid for 2026 reimbursement.

Inclusion terms cover mesiodens, distomolar, fourth molar, paramolar, and supplementary teeth.

K00.1 carries a Type 2 Excludes note for K01 (embedded and impacted teeth), meaning both codes can be reported together when clinically documented, but sequencing should follow payer-specific rules.

Pabau’s claims management software helps oral health practices attach K00.1 correctly to claims and avoid denials.

Supernumerary teeth create real documentation challenges for dental and oral health coders. When an extra tooth shows up on a radiograph or requires surgical treatment, the claim needs an exact diagnosis code to support medical necessity and clear the payer review. ICD-10 Code K00.1 is that code, and getting its documentation right determines whether the claim pays or gets denied. This reference guide covers K00.1’s billable status, inclusion terms, sequencing rules, related codes, and the documentation your practice needs to support reimbursement. You’ll also find guidance on related ICD-10-CM diagnostic codes used alongside oral cavity conditions.

ICD-10 Code K00.1: definition and billable status

ICD-10 Code K00.1 is a billable, specific ICD-10-CM code for supernumerary teeth. It carries a valid status for fiscal year 2026 and can be used on claims submitted for reimbursement without requiring a more specific subcode.

The code sits within the K00-K14 block (Diseases of oral cavity and salivary glands) inside Chapter 11 (Diseases of the digestive system) of the CDC/NCHS ICD-10-CM classification. Its parent code is K00 (Disorders of tooth development and eruption), making it one of ten K00 subcodes covering everything from anodontia to teething syndrome.

Because K00.1 is a specific, billable code rather than a category header, coders do not need to search for a more specific subcode. It reports the condition on its own.

Supernumerary teeth: clinical overview

Supernumerary teeth are extra teeth that develop beyond the normal complement of 20 primary or 32 permanent teeth. They affect roughly 1-4% of the general population, according to AAPC Codify coding references and published dental literature, and they are more common in the maxillary arch than the mandibular arch.

Clinically, supernumerary teeth present in several distinct forms. Coders should understand the subtypes because they appear directly in K00.1’s inclusion terms.

• Mesiodens: a small, peg-shaped supernumerary tooth that erupts between the maxillary central incisors. It’s the most common subtype and frequently causes spacing problems or prevents normal incisor eruption.
• Distomolar: an extra molar positioned distal to the third molar, sometimes called a fourth molar. Usually erupts in the maxillary arch.
• Paramolar: a supernumerary molar located buccally or lingually alongside an existing molar, rather than distal to it.
• Supplemental teeth: a tooth that mirrors a normal tooth in the series in shape and size, most often found in the incisor or premolar region.

All four subtypes fall under ICD-10 Code K00.1. When the radiograph or operative note identifies the specific subtype, document it in the clinical record. It strengthens medical necessity even though the code does not separate them.

K00.1 inclusion terms and synonyms

The official ICD-10-CM tabular list provides inclusion terms for K00.1 that coders should match against clinical documentation. These terms confirm the code applies and support clean claim filing through your claims management software.

• Distomolar
• Fourth molar
• Mesiodens
• Paramolar
• Supplemental teeth

If the treating clinician’s note uses any of these terms to describe the tooth anomaly, K00.1 is the appropriate code. “Supernumerary tooth,” “extra tooth,” or “accessory tooth” are also acceptable clinical equivalents. Document exactly what appears in the radiograph report or operative note.

K00.1 sequencing rules and excludes notes

Order matters when K00.1 appears alongside other oral cavity codes. Payers and groupers apply the CMS ICD-10-CM Official Guidelines to check code pairings, and a sequencing error can trigger a denial even when the individual codes are correct.

Type 2 Excludes: K00 and K01

The K00 parent code carries a Type 2 Excludes note for K01 (Embedded and impacted teeth). A Type 2 Excludes note means the excluded condition is different enough from K00 that it may be coded separately when both conditions are present and documented. However, K01.1 (Impacted teeth) describes a tooth that is blocked from erupting by a physical block, while K00.1 describes the presence of a numerically extra tooth. They are different clinical conditions.

The coding risk: a supernumerary tooth that is also impacted. In that scenario, a clinician may document both conditions. Check whether the payer accepts both codes on the same claim or requires a single main diagnosis. Without clear documentation of both, do not assume both codes apply.

Principal vs. secondary diagnosis sequencing

When K00.1 is the reason for the visit, sequence it as the main diagnosis. When supernumerary teeth are discovered by chance during treatment for another condition, sequence the primary condition first and K00.1 as a secondary code. For inpatient visits, follow Chapter 11 and UHDDS sequencing rules as published in the annual CMS guidelines.

Related codes adjacent to ICD-10 Code K00.1

Accurate coding for tooth development disorders requires familiarity with the full K00 subcode set and the adjacent K01 codes. The table below maps the K00 family so coders can locate the right code when documentation points to a different condition. For broader coding context, see adjacent ICD-10 coding guides for other organ systems.

The most common coding confusion is between K00.1 and K01.1. Supernumerary teeth (K00.1) refers to the existence of an extra tooth. Impacted teeth (K01.1) refers to a tooth that cannot erupt due to physical obstruction. A supernumerary tooth can cause another tooth to become impacted, but that result codes to K01.1, not K00.1.

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ICD-10 Code K00.1 documentation requirements

Payers require documentation that supports both the diagnosis and any intervention billed. For K00.1, the documentation package typically includes the items below. Using structured digital intake forms for dental patients ensures this information is captured at the point of care rather than assembled after the fact before a claim goes out.

Clinical documentation checklist

• Radiographic evidence: Periapical, panoramic, or CBCT images showing the supernumerary tooth. Include the date taken and the clinician’s findings.
• Clinical examination notes: Document whether the tooth is erupted, partially erupted, or unerupted. Note its location (maxillary vs. mandibular, anterior vs. posterior).
• Subtype identification: Record the specific term if identifiable (mesiodens, distomolar, paramolar, supplemental). This ties directly to the K00.1 inclusion terms.
• Medical necessity narrative: Explain why the supernumerary tooth requires treatment. Common reasons include crowding, impaction of adjacent teeth, risk of disease, or patient symptoms.
• Treatment plan or procedure note: If extraction or surgical removal is planned or performed, document the rationale and link it to the K00.1 diagnosis.
• Pediatric considerations: For patients under 18, note whether the supernumerary tooth is primary or permanent dentition and the stage of adjacent tooth development.

Pre-authorization requirements vary by payer. Some medical insurance plans cover extraction of supernumerary teeth when the procedure is medically necessary and documented as causing pathology or functional impairment. Dental plans may apply different coverage rules. Confirm payer-specific rules before filing.

Integrating ICD-10 Code K00.1 into practice billing workflows

Oral health and dental practices that bill medical insurance for supernumerary tooth procedures need a clean workflow from diagnosis capture to claim submission. Gaps between the clinical note and the billing system are where K00.1 claims most often fail.

Accurate patient records are the foundation. When the clinician records the supernumerary tooth in the patient’s chart with the correct subtype and radiographic findings, the coder has the evidence needed to apply K00.1 safely. Practices using paper records or separate billing systems often miss this link.

• Capture at the point of care: Build K00.1 into oral health intake and clinical templates so it appears as a selectable diagnosis when radiographs show extra teeth.
• Link CDT codes to K00.1: Common CDT procedure codes paired with K00.1 include D7210 (surgical extraction), D7240 (removal of impacted tooth, complete bony), and D7111 (extraction, coronal remnants — primary/deciduous tooth coronal remnants only; not applicable to permanent supernumerary tooth extraction). The ICD code supports the CDT procedure on the medical claim.
• Confirm the correct claim form: Supernumerary tooth extractions billed to medical insurance typically use the CMS-1500 claim form with K00.1 as the diagnosis. Dental claims use the ADA dental claim form with CDT codes. Payer requirements on which form to use vary.
• Track pre-authorization status: Record approval reference numbers alongside the K00.1 diagnosis in the patient record before the procedure date.

For practices managing multiple insurance types and both medical and dental claims, see how other ICD-10 code references handle dual-claim workflows and apply the same approach to K00.1 encounters.

Conclusion

Supernumerary teeth are an uncommon finding, but when they appear, getting ICD-10 Code K00.1 right determines whether the claim pays on the first pass. The code is billable, valid for 2026, and supported by clear inclusion terms covering mesiodens, distomolar, paramolar, and supplemental teeth.

The documentation requirements are straightforward when the clinical team captures the right details at the point of care. Pabau’s integrated claims management tools help oral health practices keep diagnosis coding, patient records, and claim submission connected so K00.1 encounters don’t stall in the billing queue. Book a demo to see how Pabau supports dental and oral health billing workflows.

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