K12: Stomatitis and related lesions
Codes under K12 (Stomatitis and related lesions). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| K12.0 | Recurrent oral aphthae | ✓ |
| K12.0 | Recurrent oral aphthae | ✓ |
| K12.1 | Other forms of stomatitis | ✓ |
| K12.1 | Other forms of stomatitis | ✓ |
| K12.2 | Cellulitis and abscess of mouth | ✓ |
| K12.2 | Cellulitis and abscess of mouth | ✓ |
| K12.3 | Oral mucositis (ulcerative) | — |
| K12.3 | Oral mucositis (ulcerative) | — |
| K12.30 | Oral mucositis (ulcerative), unspecified | ✓ |
| K12.30 | Oral mucositis (ulcerative), unspecified | ✓ |
| K12.31 | Oral mucositis (ulcerative) due to antineoplastic therapy | ✓ |
| K12.31 | Oral mucositis (ulcerative) due to antineoplastic therapy | ✓ |
| K12.32 | Oral mucositis (ulcerative) due to other drugs | ✓ |
| K12.32 | Oral mucositis (ulcerative) due to other drugs | ✓ |
| K12.33 | Oral mucositis (ulcerative) due to radiation | ✓ |
| K12.33 | Oral mucositis (ulcerative) due to radiation | ✓ |
| K12.39 | Other oral mucositis (ulcerative) | ✓ |
| K12.39 | Other oral mucositis (ulcerative) | ✓ |
Frequently asked questions
What is ICD-10-CM code K12?
K12 is an ICD-10-CM category covering Stomatitis and related lesions. It contains 18 more specific diagnosis codes, 16 of which are billable.
Is K12 a billable code?
No — K12 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example K12.0 — Recurrent oral aphthae). 16 of the 18 codes under K12 are billable.
What codes fall under K12?
K12 includes K12.0, K12.0, K12.1, K12.1, K12.2, plus 13 more. See the full list with descriptions and billable status above.
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Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
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