K12.31 Oral mucositis (ulcerative) due to antineoplastic therapy

The ICD-10-CM code for Oral mucositis (ulcerative) due to antineoplastic therapy is K12.31 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

11: Diseases of the digestive system (K00-K95)

Section

K00-K14: Diseases of oral cavity and salivary glands (K00-K14)

Category K12

10 codes (8 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to K12.31:

• Mucositis (ulcerative) › mouth (oral) (oropharyngeal) › due to antineoplastic therapy

U.S. Hospital Utilization

• An estimated 11,270 U.S. inpatient stays in 2023 included K12.31 among the documented diagnoses.
• 1,020 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Chapter 11 reserved for future expansion

11. Chapter 11: Diseases of the Digestive System (K00-K95) Reserved for future guideline expansion

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)