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  6. 2024 ICD-10-CM Code K65
Version 2024
Non-Billable Code

2024 ICD-10-CM Diagnosis Code K65

Peritonitis

ICD-10-CM Code:
K65
ICD-10 Code for:
Peritonitis
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Diseases of the digestive system
    (K00–K95)
    • Diseases of peritoneum and retroperitoneum
      (K65-K68)
      • Peritonitis
        (K65)

K65 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of peritonitis. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Peritonitis

Non-specific codes like K65 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for peritonitis:

  • Use K65.0 for Generalized (acute) peritonitis - BILLABLE CODE

  • Use K65.1 for Peritoneal abscess - BILLABLE CODE

  • Use K65.2 for Spontaneous bacterial peritonitis - BILLABLE CODE

  • Use K65.3 for Choleperitonitis - BILLABLE CODE

  • Use K65.4 for Sclerosing mesenteritis - BILLABLE CODE

  • Use K65.8 for Other peritonitis - BILLABLE CODE

  • Use K65.9 for Peritonitis, unspecified - BILLABLE CODE

Clinical Information

  • Chylous Ascites

    presence of milky lymph (chyle) in the peritoneal cavity, with or without infection.

  • Coronavirus, Feline

    a species of coronavirus infecting cats of all ages and commonly found in catteries and zoos. cats are often found carrying the virus but only a small proportion develop disease. feline coronavirus and feline infectious peritonitis virus (fipv) are virtually the same virus in genetic and antigenetic terms, and are morphologically indistinguishable. since they only differ in their disease potential (with fipv causing a more serious illness), they are considered biotypes of each other.

  • Familial Mediterranean Fever

    a group of hereditary autoinflammation diseases, characterized by recurrent fever, abdominal pain, headache, rash, pleurisy; and arthritis. orchitis; benign meningitis; and amyloidosis may also occur. homozygous or compound heterozygous mutations in marenostrin gene encoding pyrin result in autosomal recessive transmission; simple heterozygous, autosomal dominant form of the disease also exists with mutations in the same gene.

  • Feline Infectious Peritonitis

    common coronavirus infection of cats caused by the feline infectious peritonitis virus (coronavirus, feline). the disease is characterized by a long incubation period, fever, depression, loss of appetite, wasting, and progressive abdominal enlargement. infection of cells of the monocyte-macrophage lineage appears to be essential in fip pathogenesis.

  • Peritonitis

    inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs.

  • Peritonitis, Tuberculous

    a form of peritonitis seen in patients with tuberculosis, characterized by lesion either as a miliary form or as a pelvic mass on the peritoneal surfaces. most patients have ascites, abdominal swelling, abdominal pain, and other systemic symptoms such as fever; weight loss; and anemia.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Code Also

Code Also
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
  • if applicable diverticular disease of intestine K57

Use Additional Code

Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an additional code.

Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • 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

Patient Education


Peritoneal Disorders

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 the problem. Treatment of peritoneal disorders depends on the cause.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.