ICD-10-CM 2027
ICD-10 code for omentum tuberculosis
From the official ICD-10-CM alphabetic index entry “Tuberculosis, tubercular, tuberculous (calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative) › omentum”. Page updated September 29, 2026.
About coding omentum tuberculosis
The ICD-10-CM code for omentum tuberculosis is A18.31 (Tuberculous peritonitis).
Within A18.3 (tuberculosis of intestines, peritoneum and mesenteric glands), A18.31 is specifically for tuberculous peritonitis. Related codes cover tuberculous enteritis (A18.32) and retroperitoneal tuberculosis (A18.39).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 371 (Major Gastrointestinal Disorders and Peritoneal Infections with MCC, relative weight 1.7089), DRG 372 (Major Gastrointestinal Disorders and Peritoneal Infections with CC, relative weight 0.9964), DRG 373 (Major Gastrointestinal Disorders and Peritoneal Infections without CC/MCC, relative weight 0.6941), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506), DRG 975 (HIV with Major Related Condition with CC, relative weight 1.3252) and DRG 976 (HIV with Major Related Condition without CC/MCC, relative weight 0.8124), in MDC 06 (Diseases and Disorders of the Digestive System) and MDC 25 (Human Immunodeficiency Virus Infections), 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 omentum tuberculosis ICD-10 codes
What is the ICD-10 code for omentum tuberculosis?
- A18.31 — Tuberculous peritonitis.
Is A18.31 billable?
- Yes. A18.31 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A18.31 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A18.31 as a principal diagnosis.
Is A18.31 a CC or MCC?
- A18.31 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.