ICD-10-CM 2027
ICD-10 code for mucositis
From the official ICD-10-CM alphabetic index entry “Mucositis (ulcerative)”. Page updated September 29, 2026.
About coding mucositis
The ICD-10-CM code for mucositis is K12.30 (Oral mucositis (ulcerative), unspecified). The official index lists 10 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on K12.30.
Within K12.3, choose K12.30 (unspecified) only when documentation doesn't support a more specific option: due to antineoplastic therapy (K12.31), due to other drugs (K12.32), due to radiation (K12.33) and other oral mucositis (ulcerative) (K12.39).
Use an additional code to identify: alcohol abuse and dependence (F10.-), exposure to environmental tobacco smoke (Z77.22), exposure to tobacco smoke in the perinatal period (P96.81), history of tobacco dependence (Z87.891), occupational exposure to environmental tobacco smoke (Z57.31) and 2 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
More specific mucositis codes (official index)
- due to drugs NEC K12.32 — Oral mucositis (ulcerative) due to other drugs
- gastrointestinal K92.81 — Gastrointestinal mucositis (ulcerative)
- mouth (oral) (oropharyngeal) K12.30 — Oral mucositis (ulcerative), unspecified
- due to antineoplastic therapy K12.31 — Oral mucositis (ulcerative) due to antineoplastic therapy
- due to drugs NEC K12.32 — Oral mucositis (ulcerative) due to other drugs
- due to radiation K12.33 — Oral mucositis (ulcerative) due to radiation
- specified NEC K12.39 — Other oral mucositis (ulcerative)
- viral K12.39 — Other oral mucositis (ulcerative)
- nasal J34.81 — Nasal mucositis (ulcerative)
- oral cavity
- oral soft tissues
- vagina and vulva N76.81 — Mucositis (ulcerative) of vagina and vulva
Common questions about mucositis ICD-10 codes
What is the ICD-10 code for mucositis?
- K12.30 — Oral mucositis (ulcerative), unspecified. More specific codes apply when the documentation supports them: K12.32, K92.81, K12.30, K12.31 and others below.
What is the ICD-10 code for gastrointestinal mucositis?
- K92.81 — Gastrointestinal mucositis (ulcerative).
What is the ICD-10 code for mouth mucositis?
- K12.30 — Oral mucositis (ulcerative), unspecified.
What is the ICD-10 code for nasal mucositis?
- J34.81 — Nasal mucositis (ulcerative).
What is the ICD-10 code for vagina and vulva mucositis?
- N76.81 — Mucositis (ulcerative) of vagina and vulva.
Is K12.30 billable?
- Yes. K12.30 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K12.30 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K12.30 as a principal diagnosis.
Is K12.30 a CC or MCC?
- No. K12.30 is neither a CC nor an MCC under MS-DRG v44.0.