K65.0

Billable

Generalized (acute) peritonitis

HCC Category Mapping

V28HCC 78 — Intestinal Obstruction/Perforation

0.000

V24HCC 33 — Intestinal Obstruction/Perforation

0.226

ESRDHCC 33 — Intestinal Obstruction/Perforation

0.000

What This Code Means

Generalized acute peritonitis is a serious infection and inflammation of the peritoneum, the membrane lining the abdominal cavity, affecting the entire abdomen.

Coding Tips

•This is a medical emergency; document the cause (perforation, infection source) if known for complete coding
•Distinguish from localized peritonitis by confirming the infection is generalized throughout the peritoneal cavity

Clinical Significance

K65.0 represents generalized acute peritonitis, a serious infection and inflammation of the peritoneum affecting the entire abdominal cavity. This condition is often life-threatening, requiring immediate antibiotic therapy, source control, and often surgical intervention to prevent septic shock and multi-organ failure.

Documentation Requirements

✓Clinical signs of generalized peritonitis (rebound tenderness, rigidity)
✓Evidence of acute onset and systemic involvement
✓Documentation of generalized rather than localized involvement
✓Laboratory findings supporting infection and inflammation
✓Imaging studies showing peritoneal inflammation or fluid
✓Source control measures and antibiotic therapy
✓Surgical intervention when indicated for source control
✓Intensive monitoring for sepsis and organ dysfunction

Commonly Confused Codes

K65.1 — Peritoneal abscess (localized collection rather than generalized inflammation)K65.2 — Spontaneous bacterial peritonitis (specific type in cirrhotic patients)K65.8 — Other peritonitis (when specific type is documented)K63.1 — Perforation of intestine (underlying cause rather than peritonitis)R10.0 — Acute abdomen (symptom rather than specific diagnosis)

Code Hierarchy

└K65Peritonitis └K65.0Generalized (acute) peritonitis

└K65.0Generalized (acute) peritonitis