K26 vs K63.1
K26 and K63.1 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 K63.1
perforation (nontraumatic) of duodenum (K26.-)
K26
Duodenal ulcer
Not billable
- Chapter 11
- Diseases of the digestive system
- Section
- K20-K31
Use when the record says
- erosion (acute) of duodenum
- duodenum ulcer (peptic)
- postpyloric ulcer (peptic)
K63.1
Perforation of intestine (nontraumatic)
Billable
- Chapter 11
- Diseases of the digestive system
- Section
- K55-K64
Use when the record says
- Perforation (nontraumatic) of rectum
Indexed under
- Perforation, perforated › bowel (nontraumatic) (of)
- Perforation, perforated › colon (nontraumatic) (of)
- Perforation, perforated › ileum (nontraumatic) (of)
- Perforation, perforated › intestine NEC (nontraumatic) (of)
- Perforation, perforated › jejunum, jejunal (nontraumatic) (of)
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