K12.3

Oral mucositis (ulcerative)

FY2027Chapter 11: Diseases of the digestive system/K00–K14 Diseases of oral cavity and salivary glands

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

K12.3 is a non-billable ICD-10-CM code header for oral mucositis (ulcerative). Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are K12.30 Oral mucositis (ulcerative), unspecified; K12.31 Oral mucositis (ulcerative) due to antineoplastic therapy; K12.32 Oral mucositis (ulcerative) due to other drugs; K12.33 Oral mucositis (ulcerative) due to radiation and 1 more. Its coding notes include a Use additional code instruction, 5 Excludes1 entries and 11 Excludes2 entries.

Use additional code

Add the listed code as a secondary code, if known.

Inherited from K12 Stomatitis and related lesions
  • 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)
    • tobacco dependence (F17.-)
    • tobacco use (Z72.0)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from K12 Stomatitis and related lesions
  • cancrum oris (A69.0)
  • cheilitis (K13.0)
  • gangrenous stomatitis (A69.0)
  • herpesviral [herpes simplex] gingivostomatitis (B00.2)
  • noma (A69.0)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • gastrointestinal mucositis (ulcerative) (K92.81)
  • mucositis (ulcerative) of vagina and vulva (N76.81)
  • nasal mucositis (ulcerative) (J34.81)
Also from chapter/block level (8 notes)
Inherited from Chapter 11 Diseases of the digestive system
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Inclusion terms

Conditions classified to this code.

This code
  • Mucositis (oral) (oropharyneal)

More specific codes under K12.3 5