K12.1
Other forms of stomatitis
K12.1 (also written K121) is a billable ICD-10-CM diagnosis code for other forms of stomatitis. It is part of the FY2027 code set, effective October 1, 2026. It is one of the 8 codes in category K12 (Stomatitis and related lesions). The Alphabetic Index lists it under 13 entries. Its coding notes include a Use additional code instruction, 7 Excludes1 entries and 8 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
- code to identify:
Excludes1
Not coded here. The listed conditions generally should not be reported together.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Care settings
How CMS programs treat this code. These are CMS claim edits and list entries, not coverage or eligibility rules.
Home Health Primary
Accepted as the primary (principal) diagnosis on a home health claim. The Home Health Grouper assigns it to the MMTA - Gastrointestinal tract and Genitourinary system clinical group.
Source: CMS Home Health Grouper Software v07.2.26, effective October 1, 2026Inclusion terms
Conditions classified to this code.
- Stomatitis NOS
- Denture stomatitis
- Ulcerative stomatitis
- Vesicular stomatitis
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 13 entries
- Catarrh, catarrhal (acute) (febrile) (infectious) (inflammation), mouth
- Inflammation, inflamed, inflammatory (with exudation), mouth
- Stomatitis (denture) (ulcerative)
- Stomatitis (denture) (ulcerative), catarrhal
- Stomatitis (denture) (ulcerative), follicular
- Stomatitis (denture) (ulcerative), malignant
- Stomatitis (denture) (ulcerative), membranous acute
- Stomatitis (denture) (ulcerative), septic
- Stomatitis (denture) (ulcerative), vesicular
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative, buccal (cavity) (traumatic)
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative, oral mucosa (traumatic)
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative, palate (soft)