A18.39Retroperitoneal tuberculosis

A18.39 is the ICD-10-CM diagnosis code for retroperitoneal tuberculosis. It belongs to category A18 (tuberculosis of other organs), block A15-A19 (tuberculosis) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within A18.3 (tuberculosis of intestines, peritoneum and mesenteric glands), A18.39 is specifically for retroperitoneal tuberculosis. Related codes cover tuberculous peritonitis (A18.31) and tuberculous enteritis (A18.32).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" 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.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 014.80 (other tuberculosis of intestines, peritoneum, and mesenteric glands, unspecified).