ICD-10 Code K65.1 – Peritoneal Abscess (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code K65.1 – Peritoneal abscess
What it is
K65.1 identifies a localized collection of pus within the peritoneal cavity. Use it when documentation states a peritoneal abscess, not just generalized peritonitis or abdominal infection.
Clinical signs
Clinical features vary; refer to documentation. Commonly recorded findings include abdominal pain, tenderness, fever, and signs of localized intra-abdominal infection on imaging or operative report.
When to use this code
Use K65.1 when the provider documents a peritoneal abscess, including postoperative or secondary intra-abdominal abscess involving the peritoneal cavity. It may be supported by imaging, drainage findings, or surgical notes. If the record only says peritonitis or abdominal abscess, check documentation.
Do not use for
Do not assign this code for generalized peritonitis without a documented abscess. Do not use it for abscesses clearly located in another site, such as liver, appendix, or pelvic organs, unless the peritoneum is specifically involved.
Coding tip
Code the abscess only when the provider clearly documents the peritoneal location; if the site is unclear, query for specificity.