ICD-10 Code K66.1 – Hemoperitoneum (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K66.1 – Hemoperitoneum
What it is
Hemoperitoneum means blood is present in the peritoneal cavity, the space inside the abdomen. Use this code when documentation clearly identifies intra-abdominal bleeding into that space.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include abdominal pain, distension, tenderness, or signs of internal bleeding, but the record should support the diagnosis.
When to use this code
Use K66.1 when the provider documents hemoperitoneum, such as after trauma, a ruptured abdominal organ, or another confirmed source of intraperitoneal bleeding. Code it when the diagnosis is established, not merely suspected. Check documentation if the note only describes free fluid or abdominal pain.
Do not use for
Do not use this code for gastrointestinal bleeding, retroperitoneal hemorrhage, or unspecified abdominal pain without documented blood in the peritoneal cavity. If the site of bleeding is different, choose the more specific diagnosis.
Coding tip
Confirm that the provider explicitly links the bleeding to the peritoneal cavity before assigning K66.1.