A18.31 vs K65
A18.31 (Tuberculous peritonitis) compared with K65 (Peritonitis), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. K65 carries an Excludes1 note covering A18.31: “peritonitis in tuberculosis (A18.31)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| A18.31Tuberculous peritonitis | K65Peritonitis | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | A00-B99 — Certain Infectious and Parasitic Diseases (A00-B99) | K00-K95 — Diseases of the Digestive System (K00-K95) |
| Definition | Tuberculous peritonitis is a billable ICD-10-CM diagnosis code (A18.31). | Peritonitis is a non-billable ICD-10-CM category code (K65). |
| Includes | infections due to Mycobacterium tuberculosis and Mycobacterium bovis Tuberculous ascites | — |
| Use additional code | code, if applicable, for associated cachexia (E88.A) | code (B95-B97), to identify infectious agent, if known |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources