ICD-10 Code for Canker

The default ICD-10-CM 2027 code for canker (mouth) (sore) is K12.0 – Recurrent oral aphthae. More specific codes depend on the details documented, as listed in the official index (2 codes, 2 billable).

Main code
K12.0 – Recurrent oral aphthae
Billable
Yes

Index entries for Canker

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.