K12.0 — Recurrent oral aphthae
K12.0 is a billable, specific ICD-10-CM code for recurrent oral aphthae. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Aphthous stomatitis (major) (minor)
- Bednar's aphthae
- Periadenitis mucosa necrotica recurrens
- Recurrent aphthous ulcer
- Stomatitis herpetiformis
Excludes1 inherited from the categories above K12.0
These are not written on K12.0, but they bind it: a note on a category applies to every code beneath it. Billing K12.0 with anything listed here is a denial.
Risk adjustment
K12.0 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
K12.0 is named in 1 Medicare coverage policy — 1 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A54111Billing and Coding: Speech Language Pathology (SLP) Services: Communication Disorders
How K12.0 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to K12.0.
- Canker(mouth) (sore)
- Periadenitis mucosa necrotica recurrens
- Aphthae, aphthous›Bednar's
- Aphthae, aphthous›oral(recurrent)
- Aphthae, aphthous›stomatitis(major) (minor)
- Aphthae, aphthous›ulcer(oral) (recurrent)
- Bednar's›aphthae
- Stomatitis›aphthous
- Stomatitis›herpetiformis
- Ulcer, ulcerated, ulcerating, ulceration, ulcerative›aphthous(oral) (recurrent)
- Sore›mouth›canker
Code history
K12.0 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share K12. If K12.0 is not quite right, the correct code is usually one of these.
Questions about K12.0
- Is K12.0 a billable ICD-10-CM code?
- Yes. K12.0 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does K12.0 sit in the tabular list?
- Diseases of the digestive system (K00-K95), in the block Diseases of oral cavity and salivary glands (K00-K14).
- What cannot be coded together with K12.0?
- K12.0 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above K12.0 (K12) and apply to it just the same.