A69.1 vs K12.1
A69.1 and K12.1 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on K12.1
acute necrotizing ulcerative stomatitis (A69.1)
A69.1
Other Vincent's infections
Billable
- Chapter 1
- Certain infectious and parasitic diseases
- Section
- A65-A69
Use when the record says
- Fusospirochetal pharyngitis
- Necrotizing ulcerative (acute) gingivitis
- Necrotizing ulcerative (acute) gingivostomatitis
- Spirochetal stomatitis
- Trench mouth
- Vincent's angina
- Vincent's gingivitis
Indexed under
- Fusospirillosis (mouth) (tongue) (tonsil)
- Plautdisease (-Vincent)
- Vincent's infection (angina) (gingivitis)
- Angina › pseudomembranous (attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
- Angina › Vincent's (attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
K12.1
Other forms of stomatitis
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K00-K14
Use when the record says
- Stomatitis NOS
- Denture stomatitis
- Ulcerative stomatitis
- Vesicular stomatitis
Indexed under
- Stomatitis (denture) (ulcerative)
- Catarrh, catarrhal › mouth (acute) (febrile) (infectious) (inflammation)
- Inflammation, inflamed, inflammatory › mouth (with exudation)
- Stomatitis › catarrhal (denture) (ulcerative)
- Stomatitis › follicular (denture) (ulcerative)
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027