ICD-10 Code K09.9 – Cyst of oral region, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K09.9 – Cyst of oral region, unspecified
What it is
K09.9 identifies an unspecified cyst in the oral region. Use it when the record documents a cyst in the mouth or oral tissues, but does not name a specific type or site.
Clinical signs
Clinical features vary; refer to documentation. Oral cysts may appear as a localized swelling, lump, or radiographic finding in the mouth, but the exact appearance depends on the cyst type and location.
When to use this code
Use this code when the provider documents a cyst of the oral region without further detail. It is appropriate when the site is oral but the record does not specify a more exact diagnosis. If the note identifies a specific cyst type or jaw location, code that more specific option instead.
Do not use for
Do not use K09.9 when the documentation names a different oral lesion, a salivary gland disorder, or a clearly identified cyst type. Check documentation if the record is vague but suggests another diagnosis.
Coding tip
Assign the unspecified code only when the chart lacks enough detail for a more specific oral cyst code.