2026 ICD-10-CM Diagnosis Code K13.5Oral submucous fibrosis
ICD-10-CM Codes›K00–K95›K00-K14›K13
- Billable — Valid for Submission
- Chronic Condition
K13.5 is a billable ICD-10-CM diagnosis code for oral submucous fibrosis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 157 through 159. Coders also document this condition as oral submucosal fibrosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury, Diseases of mouth; excluding dental, and Nontraumatic dental conditions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Oral submucosal fibrosis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Submucous fibrosis of tongue
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- submucous (oral) (tongue) - K13.5
- tongue, submucous - K13.5
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Fibrosis, fibrotic
- submucous (oral) (tongue)
- Fibrosis, fibrotic
- tongue, submucous
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Oral Submucous Fibrosis
irreversible fibrosis of the submucosal tissue of the mouth.
Patient EducationClinical
Mouth Disorders
Your mouth is one of the most important parts of your body. It has many different functions. It allows you to:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert K13.5 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K13.5Overview
Is K13.5 (Other diseases of lip and oral mucosa) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report oral submucous fibrosis on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does K13.5 group to?
When oral submucous fibrosis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 157, 158, 159, with relative weights from 0.7085 to 1.7168 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of K13.5?
Under the General Equivalence Mappings, oral submucous fibrosis converts to ICD-9-CM 528.8 (oral submucosal fibrosis). The mapping is a direct match.
Footnotes
[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:
- The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
- The condition places limitations on self-care, independent living, and social interactions.
