ICD-10 Code K04.8 – Radicular cyst (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K04.8 – Radicular cyst
What it is
K04.8 identifies a radicular cyst, a cystic lesion that usually develops at the root of a nonvital tooth. It is typically related to chronic inflammation from pulpal infection.
Clinical signs
Findings may include a slow-growing, often painless swelling near an affected tooth. Imaging may show a well-defined radiolucent area at the tooth apex; clinical features vary, so refer to documentation.
When to use this code
Use K04.8 when the record documents a radicular cyst, including an apical cyst associated with a diseased or nonvital tooth. Apply it when the diagnosis is confirmed clinically, radiographically, or by pathology. If the note only says “dental cyst,” check documentation for the exact type.
Do not use for
Do not use this code for other odontogenic cysts, periapical abscess, or general tooth infection unless a radicular cyst is specifically documented. Check documentation if the lesion type is unclear.
Coding tip
Code K04.8 only when the provider clearly links the cyst to a radicular origin or names it directly.