K12.3 – Oral mucositis (ulcerative)

ICD-10-CM 2027 diagnosis code · Diseases of oral cavity and salivary glands

Non-billable header

ICD-10-CM code K12.3
Code
K12.3 (claims format: K123)
Description
Oral mucositis (ulcerative)
Billable
No – use a more specific code below
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
11. Diseases of the digestive system (K00-K95)
Block
K00-K14 Diseases of oral cavity and salivary glands
Parent codes
K12

Billable codes under K12.3

K12.3 is a header code and cannot be used on claims. Choose the most specific code:

Notes for K12.3

Applicable to:
  • Mucositis (oral) (oropharyneal)
Excludes2 (not included here):
  • gastrointestinal mucositis (ulcerative) (K92.81)
  • mucositis (ulcerative) of vagina and vulva (N76.81)
  • nasal mucositis (ulcerative) (J34.81)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

K12 – Stomatitis and related lesions

Excludes1 (not coded here):
  • cancrum oris (A69.0)
  • cheilitis (K13.0)
  • gangrenous stomatitis (A69.0)
  • herpesviral [herpes simplex] gingivostomatitis (B00.2)
  • noma (A69.0)
Use additional code:
  • 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)

Related codes in K12

Frequently asked questions

What is ICD-10 code K12.3?

K12.3 is the ICD-10-CM code for oral mucositis (ulcerative), in the block K00-K14 (Diseases of oral cavity and salivary glands).

Is K12.3 a billable code?

No. K12.3 is a header code with more specific child codes; report one of the billable codes listed above.

What category does K12.3 belong to?

It belongs to category K12 – Stomatitis and related lesions.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.