Other diseases of lip and oral mucosa (K13) ICD-10-CM
The K13 code range covers other diseases of lip and oral mucosa with 16 ICD-10-CM diagnosis codes. 13 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- epithelial disturbances of tongue
Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an 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
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
Codes in the K13 Range 16 codes · 13 billable
- K13 Other diseases of lip and oral mucosaNon-billable
- K13.0 Diseases of lips
- K13.1 Cheek and lip biting
- K13.2 Leukoplakia and other disturbances of oral epithelium, including tongueNon-billable
- K13.21 Leukoplakia of oral mucosa, including tongue
- K13.22 Minimal keratinized residual ridge mucosa
- K13.23 Excessive keratinized residual ridge mucosa
- K13.24 Leukokeratosis nicotina palati
- K13.29 Other disturbances of oral epithelium, including tongue
- K13.3 Hairy leukoplakia
- K13.4 Granuloma and granuloma-like lesions of oral mucosa
- K13.5 Oral submucous fibrosis
- K13.6 Irritative hyperplasia of oral mucosa
- K13.7 Other and unspecified lesions of oral mucosaNon-billable
- K13.70 Unspecified lesions of oral mucosa
- K13.79 Other lesions of oral mucosa
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the K13 range.
Cheilitis
Inflammation of the lips. It is of various etiologies and degrees of pathology.
Churg-Strauss Syndrome
Widespread necrotizing angiitis with granulomas. Pulmonary involvement is frequent. Asthma or other respiratory infection may precede evidence of vasculitis. Eosinophilia and lung involvement differentiate this disease from POLYARTERITIS NODOSA.
Eosinophilic Granuloma
The most benign and common form of Langerhans-cell histiocytosis which involves localized nodular lesions predominantly of the bones but also of the gastric mucosa, small intestine, lungs, or skin, with infiltration by EOSINOPHILS.
Eosinophils
Granular leukocytes with a nucleus that usually has two lobes connected by a slender thread of chromatin, and cytoplasm containing coarse, round granules that are uniform in size and stainable by eosin.
Kimura Disease
A chronic inflammatory disease characterized by benign enlargement of cervical LYMPH NODE and SALIVARY GLANDS with increased levels of IMMUNOGLOBULIN E. Unlike ANGIOLYMPHOID HYPERPLASIA WITH EOSINOPHILIA it involves eosinophil infiltrates in lymph node and salivary glands and mostly found in Asian males.
Leukoplakia
A white patch lesion found on a MUCOUS MEMBRANE that cannot be scraped off. Leukoplakia is generally considered a precancerous condition, however its appearance may also result from a variety of HEREDITARY DISEASES.
Leukoplakia, Hairy
Epithelial hyperplasia of the oral mucosa associated with Epstein-Barr virus (HERPESVIRUS 4, HUMAN) and found almost exclusively in persons with HIV infection. The lesion consists of a white patch that is often corrugated or hairy.
Leukoplakia, Oral
A white patch seen on the oral mucosa. It is considered a premalignant condition and is often tobacco-induced. When evidence of Epstein-Barr virus is present, the condition is called hairy leukoplakia (LEUKOPLAKIA, HAIRY).
Melkersson-Rosenthal Syndrome
An idiopathic syndrome characterized by one or more of the following; recurrent orofacial swelling, relapsing facial paralysis, and fissured tongue (lingua plicata). The onset is usually in childhood and relapses are common. Cheilitis granulomatosa is a monosymptomatic variant of this condition. (Dermatol Clin 1996 Apr;14(2):371-9; Magalini & Magalini, Dictionary of Medical Syndromes, 4th ed, p531)
Oral Submucous Fibrosis
Irreversible FIBROSIS of the submucosal tissue of the MOUTH.
Polyarteritis Nodosa
A form of necrotizing non-granulomatous inflammation occurring primarily in medium-sized ARTERIES, often with microaneurysms. It is characterized by muscle, joint, and abdominal pain resulting from arterial infarction and scarring in affected organs. Polyarteritis nodosa with lung involvement is called CHURG-STRAUSS SYNDROME.
About the K13 Code Range
The ICD-10 code K13 covers various other diseases of the lip and oral mucosa, including a wide range of specific conditions affecting these areas. This section is used to classify diseases such as lip disorders, cheek and lip biting, leukoplakia, granulomatous lesions, and other oral mucosal conditions.
Codes under K13.0 address diseases of the lips, encompassing conditions like cheilitis, mucous cysts of the upper lip, and angular cheilitis, often known to coders and clinicians by terms such as "exfoliative cheilitis" or "plasma cell cheilitis." The code K13.1 is for habitual cheek and lip biting, also called lip biting or biting of the oral mucosa. Lesions of the oral epithelium, including leukoplakia (K13.21), a common white patch that may involve the tongue, are identified using this section, helping healthcare professionals distinguish it from other oral lesions. Codes like K13.4 cover granuloma-like oral mucosa lesions, including eosinophilic granuloma and pyogenic granuloma, while K13.5 captures oral submucous fibrosis, a precancerous condition linked to fibrosis of oral tissues. Other entries include irritative hyperplasia (K13.6) and unspecified oral mucosal lesions (K13.7), which cover various inflammation, pigmentation, or ulcer conditions. These codes help coders accurately capture the diagnosis and treatment of specific lip and oral mucosa diseases beyond common dental and traumatic injuries.
Questions About This Page
How many billable codes are in the K13 range?
Of the 16 codes in this range, 13 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the K13 range classify?
The range classifies other diseases of lip and oral mucosa. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
