ICD-10-CM 2027
ICD-10 code for diffuse peritonitis
From the official ICD-10-CM alphabetic index entry “Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) › diffuse”. Page updated September 29, 2026.
About coding diffuse peritonitis
The ICD-10-CM code for diffuse peritonitis is K65.0 (Generalized (acute) peritonitis).
Within K65 (peritonitis), K65.0 is specifically for generalized (acute) peritonitis. Related codes cover peritoneal abscess (K65.1), spontaneous bacterial peritonitis (K65.2), Choleperitonitis (K65.3), sclerosing mesenteritis (K65.4), other peritonitis (K65.8) and unspecified (K65.9).
Use an additional code (B95-B97), to identify infectious agent, if known.
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.
Common questions about diffuse peritonitis ICD-10 codes
What is the ICD-10 code for diffuse peritonitis?
- K65.0 — Generalized (acute) peritonitis.
Is K65.0 billable?
- Yes. K65.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can K65.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict K65.0 as a principal diagnosis.
Is K65.0 a CC or MCC?
- K65.0 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.