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  6. 2026 ICD-10-CM Code K13.5

2026 ICD-10-CM Diagnosis Code K13.5

Oral submucous fibrosis

ICD-10-CM Code:
K13.5
ICD-10 Code for:
Oral submucous fibrosis
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

K13.5 is a billable diagnosis code used to specify a medical diagnosis of oral submucous fibrosis. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Code Classification

  • Diseases of the digestive system
    K00–K95
    • Diseases of oral cavity and salivary glands
      K00-K14
      • Other diseases of lip and oral mucosa
        K13

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Oral submucosal fibrosis

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Any dental condition including traumatic injury

CCSR Code: DEN001

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Diseases of mouth; excluding dental

CCSR Code: DIG003

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

Nontraumatic dental conditions

CCSR Code: DEN002

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Clinical Information

  • Oral Submucous Fibrosis

    irreversible fibrosis of the submucosal tissue of the mouth.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Inclusion Terms

Inclusion Terms
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.
  • Submucous fibrosis of tongue

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Fibrosis, fibrotic
      • submucous (oral) (tongue)
    • Fibrosis, fibrotic
      • tongue, submucous

Convert K13.5 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Oral submucosal fibrosis

ICD-9-CM: 528.8

This is a direct match with no additional mapping qualifiers. The absence of a flag generally means the mapping is considered exact or precise. In other words, the ICD-10 code maps cleanly to the ICD-9 code without qualification, approximation, or needing multiple codes.

View Conversion

Patient Education


Mouth Disorders

Your mouth is one of the most important parts of your body. It has many different functions. It allows you to:

  • Take in food and drink
  • Breathe in air
  • Start digestion, with your teeth chewing the food you eat and your salivary glands releasing saliva to help break down the food
  • Speak and sing
  • Show emotion, by smiling or pouting

Any problem that affects your mouth can make it hard to eat, drink, or even smile. Some common mouth problems include:

  • Cold sores - painful sores on the lips and around the mouth, caused by a virus
  • Canker sores - painful sores in the mouth, caused by bacteria or viruses
  • Thrush - a yeast infection that causes white patches in your mouth
  • Leukoplakia - white patches of excess cell growth on the cheeks, gums or tongue, common in smokers
  • Dry mouth - a lack of enough saliva, caused by some medicines and certain diseases
  • Gum or tooth problems
  • Bad breath

Treatment for mouth disorders varies, depending on the problem. If a mouth problem is caused by some other disease, treating that disease can help. It is also important to keep your mouth clean and healthy by brushing, flossing, and not using tobacco.


[Learn More in MedlinePlus]

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

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.