ICD-10-CM 2027
ICD-10 code for duodenum lesion
From the official ICD-10-CM alphabetic index entry “Lesion (s) (nontraumatic) › duodenum”. Page updated September 29, 2026.
About coding duodenum lesion
The ICD-10-CM code for duodenum lesion is K31.9 (Disease of stomach and duodenum, unspecified).
Within K31, choose K31.9 (Disease of stomach and duodenum, unspecified) only when documentation doesn't support a more specific option: acute dilatation of stomach (K31.0), adult hypertrophic pyloric stenosis (K31.1), Hourglass stricture and stenosis of stomach (K31.2), Pylorospasm, not elsewhere classified (K31.3), gastric diverticulum (K31.4), obstruction of duodenum (K31.5), fistula of stomach and duodenum (K31.6), polyp of stomach and duodenum (K31.7) and 3 more.
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 391 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders with MCC, relative weight 1.2392) and DRG 392 (Esophagitis, Gastroenteritis and Miscellaneous Digestive Disorders without MCC, relative weight 0.7645), in MDC 06 (Diseases and Disorders of the Digestive System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about duodenum lesion ICD-10 codes
What is the ICD-10 code for duodenum lesion?
- K31.9 — Disease of stomach and duodenum, unspecified.
Is K31.9 billable?
- Yes. K31.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K31.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K31.9 as a principal diagnosis.
Is K31.9 a CC or MCC?
- No. K31.9 is neither a CC nor an MCC under MS-DRG v44.0.