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Dx

ICD-10-CM 2027

ICD-10 code for stomatitis ulcer

K12.1

Other forms of stomatitis

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Ulcer, ulcerated, ulcerating, ulceration, ulcerative › stomatitis”. Page updated September 29, 2026.

About coding stomatitis ulcer

The ICD-10-CM code for stomatitis ulcer is K12.1 (Other forms of stomatitis).

Within K12, choose K12.1 (Other forms of stomatitis) only when documentation doesn't support a more specific option: recurrent oral aphthae (K12.0), cellulitis and abscess of mouth (K12.2) and oral mucositis (ulcerative) (K12.3).

Don't report K12.1 together with the conditions in its Excludes1 note: acute necrotizing ulcerative stomatitis (A69.1) and Vincent's stomatitis (A69.1).

Use an additional 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) and 2 more.

Don't confuse with (Excludes1 for K12.1)

  • acute necrotizing ulcerative stomatitis (A69.1)
  • Vincent's stomatitis (A69.1)

Common questions about stomatitis ulcer ICD-10 codes

What is the ICD-10 code for stomatitis ulcer?

K12.1 — Other forms of stomatitis.

Is K12.1 billable?

Yes. K12.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can K12.1 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict K12.1 as a principal diagnosis.

Is K12.1 a CC or MCC?

No. K12.1 is neither a CC nor an MCC under MS-DRG v44.0.