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K65

Non-billable

Peritonitis

K65 is the ICD-10-CM code for Peritonitis. It is a non-billable category code — use a more specific child code such as K65.0 for billing.

Status
Header (non-billable)
Chapter
K00-K95
Subcodes
7
Edition
FY2026

K00-K95 Diseases of the digestive system

What this means — in plain language

MedlinePlus · NIH

Your peritoneum is the tissue that lines your abdominal wall and covers most of the organs in your abdomen. A liquid, peritoneal fluid, lubricates the surface of this tissue. Disorders of the peritoneum are not common. They include: Peritonitis - an inflammation of the peritoneum Cancer Complications from peritoneal dialysis Your doctor may use imaging tests or lab tests to analyze the peritoneal fluid to diagnose…

Read more about Peritoneal Disorders at MedlinePlus ↗

Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.

Excludes1 — not coded here

  • •acute appendicitis with generalized peritonitis (K35.2-)
  • •aseptic peritonitis (T81.6)
  • •benign paroxysmal peritonitis (E85.0)
  • •chemical peritonitis (T81.6)
  • •gonococcal peritonitis (A54.85)
  • •neonatal peritonitis (P78.0-P78.1)
  • •pelvic peritonitis, female (N73.3-N73.5)
  • •periodic familial peritonitis (E85.0)
  • •peritonitis due to talc or other foreign substance (T81.6)
  • •peritonitis in chlamydia (A74.81)
  • •peritonitis in diphtheria (A36.89)
  • •peritonitis in syphilis (late) (A52.74)
  • •peritonitis in tuberculosis (A18.31)
  • •peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
  • •peritonitis with or following appendicitis (K35.-)
  • •puerperal peritonitis (O85)
  • •retroperitoneal infections (K68.-)

Use additional code

  • •code (B95-B97), to identify infectious agent, if known

Notes

  • •if applicable diverticular disease of intestine (K57.-)

Medications indicated for this condition

FDA labeling

Drugs whose FDA labeling lists this condition's category among its indications. Informational only — not a treatment recommendation or medical advice.

Frequently asked questions

What is ICD-10 code K65?
K65 is the ICD-10-CM code for "Peritonitis". It falls under K00-K95 Diseases of the digestive system.
Is K65 a billable code?
No — K65 is a non-billable header code. Use a more specific child code (such as K65.0) for billing.
What are the subcodes of K65?
K65 has 7 more specific child codes, including K65.0, K65.1, K65.2.
What is excluded from K65?
Excludes1 (not coded here): acute appendicitis with generalized peritonitis (K35.2-); aseptic peritonitis (T81.6); benign paroxysmal peritonitis (E85.0); chemical peritonitis (T81.6).

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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