2026 ICD-10-CM Diagnosis Code K12.2Cellulitis and abscess of mouth
ICD-10-CM Codes›K00–K95›K00-K14›K12
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Not Chronic
K12.2 is a billable ICD-10-CM diagnosis code for cellulitis and abscess of mouth. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 11 through 13, 157 through 159. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 9 closely related codes. 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.
- Abscess of buccal space of mouth
- Abscess of canine space of mouth
- Abscess of masticator space of mouth
- Abscess of oral soft tissue
- Abscess of oral tissue
- Abscess of palate
- Abscess of parotid masseteric region of face
- Abscess of sublingual space
- Abscess of submandibular region
- Abscess of uvula of palate
- Cellulitis and abscess of neck
- Cellulitis and abscess of submandibular region
- Cellulitis of buccal space of mouth
- Cellulitis of canine space of mouth
- Cellulitis of floor of mouth
- Cellulitis of gingiva
- Cellulitis of masticator space of mouth
- Cellulitis of neck
- Cellulitis of oral soft tissues
- Cellulitis of palate
- Cellulitis of sublingual space
- Cellulitis of submandibular region
- Cellulitis of submental space
- Dentoalveolar cellulitis
- Fistula of soft palate
- Infection of masticator space
- Ludwig's angina
- Oral fistula
- Oral sinus
- Orocutaneous fistula
- Palatitis
- Uvulitis
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Cellulitis of mouth (floor)
- Submandibular abscess
Type 2 Excludes
- abscess of salivary gland K11.3
- abscess of tongue K14.0
- periapical abscess K04.6 K04.7
- periodontal abscess K05.21
- peritonsillar abscess J36
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.
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.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) L02.91
buccal cavity K12.2
inner K12.2
mouth (floor) K12.2
palate (soft) K12.2
region K12.2
sublingual K12.2
uvula K12.2
Cellulitis (diffuse) (phlegmonous) (septic) (suppurative) L03.90
internal K12.2
mouth (floor) K12.2
palate (soft) K12.2
submaxillary (region) K12.2
Disease, diseased See Also: Syndrome;
mouth K12.2
oral (cutaneous) K12.2
region K12.2
region K12.2
mouth K12.2
submandibular K12.2
Gangrene, gangrenous (connective tissue) (dropsical) (dry) (moist) (skin) (ulcer) See Also: Necrosis; I96
uvulitis K12.2
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Ludwig's Angina
severe cellulitis of the submaxillary space with secondary involvement of the perimandibular spaces. it usually results from infection in the lower molar area or from an infection following a penetrating injury to the mouth floor.Oral Fistula
an abnormal passage within the mouth communicating between two or more anatomical structures.Mouth Floor
the area of the mouth beneath the tongue.Uvulitis
inflammation of the uvula.Orocutaneous Fistula
an abnormal communication between the skin and the oral cavity.
Patient EducationClinical
Abscess
An abscess is a pocket of pus. You can get an abscess almost anywhere in your body. When an area of your body becomes infected, your body's immune system tries to fight the infection. White blood cells go to the infected area, collect within the damaged tissue, and cause inflammation. During this process, pus forms.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert K12.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About K12.2Overview
What is the ICD-10 code for cellulitis and abscess of mouth?
The ICD-10-CM code for cellulitis and abscess of mouth is K12.2 (sometimes written as K122). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is K12.2 (Stomatitis and related lesions) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report cellulitis and abscess of mouth on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does K12.2 group to?
When cellulitis and abscess of mouth is the principal diagnosis on an inpatient stay, it groups to MS-DRG 11, 12, 13, 157, 158, 159, with relative weights from 0.7085 to 5.4541 depending on complications. Higher weights mean higher Medicare reimbursement.
Is K12.2 a CC or MCC?
CMS lists K12.2 as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 9 closely related codes in its exclusion list.
What is the ICD-9 equivalent of K12.2?
Under the General Equivalence Mappings, cellulitis and abscess of mouth converts to ICD-9-CM 528.00 (stomatitis/mucositis NOS), 528.3 (cellulitis/abscess mouth), and 682.0 (cellulitis of face). The mapping is approximate, so confirm the match fits the documentation.
