ICD-10-CM 2027
ICD-10 code for periodontal cyst
From the official ICD-10-CM alphabetic index entry “Cyst (colloid) (mucous) (simple) (retention) › periodontal”. Page updated September 29, 2026.
About coding periodontal cyst
The ICD-10-CM code for periodontal cyst is K04.8 (Radicular cyst). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on K04.8.
Within K04 (diseases of pulp and periapical tissues), K04.8 is specifically for Radicular cyst. Related codes cover pulpitis (K04.0), necrosis of pulp (K04.1), pulp degeneration (K04.2), abnormal hard tissue formation in pulp (K04.3), acute apical periodontitis of pulpal origin (K04.4), chronic apical periodontitis (K04.5), periapical abscess with sinus (K04.6), periapical abscess without sinus (K04.7) and 1 more.
The conditions in its Excludes2 note aren't part of K04.8, but may be coded alongside it if the patient has both: lateral periodontal cyst (K09.0).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific periodontal cyst codes (official index)
- lateral K09.0 — Developmental odontogenic cysts
Common questions about periodontal cyst ICD-10 codes
What is the ICD-10 code for periodontal cyst?
- K04.8 — Radicular cyst. More specific codes apply when the documentation supports them: K09.0.
What is the ICD-10 code for lateral periodontal cyst?
- K09.0 — Developmental odontogenic cysts.
Is K04.8 billable?
- Yes. K04.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K04.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K04.8 as a principal diagnosis.
Is K04.8 a CC or MCC?
- No. K04.8 is neither a CC nor an MCC under MS-DRG v44.0.