2019 ICD-10-CM Diagnosis Code K65.9

Peritonitis, unspecified

    2016 2017 2018 2019 Billable/Specific Code
  • K65.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2019 edition of ICD-10-CM K65.9 became effective on October 1, 2018.
  • This is the American ICD-10-CM version of K65.9 - other international versions of ICD-10 K65.9 may differ.
Applicable To
  • Bacterial peritonitis NOS
The following code(s) above K65.9 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to K65.9:
  • K00-K95
    2019 ICD-10-CM Range K00-K95

    Diseases of the digestive system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the digestive system
  • K65
    ICD-10-CM Diagnosis Code K65

    Peritonitis

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Code Also
    • if applicable diverticular disease of intestine (K57.-)
    Type 1 Excludes
    • 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 (B95-B97), to identify infectious agent, if known
    Peritonitis
Approximate Synonyms
  • Epiploic appendagitis
  • Fibrinous peritonitis
  • Infectious peritonitis
  • Peritoneal dialysis-associated peritonitis
  • Peritonitis
  • Peritonitis due to infected dialysis catheter
  • Peritonitis due to infected peritoneal dialysis catheter
  • Peritonitis due to peritoneal dialysis
  • Peritonitis, fibrinous
  • Peritonitis, infectious
Clinical Information
  • Inflammation of the peritoneum (tissue that lines the abdominal wall and covers most of the organs in the abdomen). Peritonitis can result from infection, injury, or certain diseases. Symptoms may include swelling of the abdomen, severe pain, and weight loss.
  • Inflammation of the peritoneum due to infection by bacteria or fungi. Causes include liver disease, perforation of the gastrointestinal tract or biliary tract, and peritoneal dialysis. Patients usually present with abdominal pain and tenderness, fever, chills, and nausea and vomiting. It is an emergency medical condition that requires prompt medical attention and treatment.
  • 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.
  • Inflammation of the peritoneum, a condition marked by exudations in the peritoneum of serum, fibrin, cells, and pus.
  • Inflammation of the thin membrane surrounding abdominal cavity, called peritoneum
ICD-10-CM K65.9 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):
  • 371 Major gastrointestinal disorders and peritoneal infections with mcc
  • 372 Major gastrointestinal disorders and peritoneal infections with cc
  • 373 Major gastrointestinal disorders and peritoneal infections without cc/mcc
  • 793 Full term neonate with major problems

Convert K65.9 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
Code annotations containing back-references to K65.9:
  • Type 1 Excludes: K65.2
    ICD-10-CM Diagnosis Code K65.2

    Spontaneous bacterial peritonitis

      2016 2017 2018 2019 Billable/Specific Code
    Type 1 Excludes
    • bacterial peritonitis NOS (K65.9)

Diagnosis Index entries containing back-references to K65.9:
  • Fistula (cutaneous) L98.8
    ICD-10-CM Diagnosis Code L98.8

    Other specified disorders of the skin and subcutaneous tissue

      2016 2017 2018 2019 Billable/Specific Code
    • peritoneum K65.9
  • Hemoperitoneum K66.1
    ICD-10-CM Diagnosis Code K66.1

    Hemoperitoneum

      2016 2017 2018 2019 Billable/Specific Code
    Type 1 Excludes
    • traumatic hemoperitoneum (S36.8-)
    • infectional K65.9
  • Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) K65.9

ICD-10-CM Codes Adjacent To K65.9
K64.5 Perianal venous thrombosis
K64.8 Other hemorrhoids
K64.9 Unspecified hemorrhoids
K65 Peritonitis
K65.0 Generalized (acute) peritonitis
K65.1 Peritoneal abscess
K65.2 Spontaneous bacterial peritonitis
K65.3 Choleperitonitis
K65.4 Sclerosing mesenteritis
K65.8 Other peritonitis
K65.9 Peritonitis, unspecified
K66 Other disorders of peritoneum
K66.0 Peritoneal adhesions (postprocedural) (postinfection)
K66.1 Hemoperitoneum
K66.8 Other specified disorders of peritoneum
K66.9 Disorder of peritoneum, unspecified
K67 Disorders of peritoneum in infectious diseases classified elsewhere
K68 Disorders of retroperitoneum
K68.1 Retroperitoneal abscess
K68.11 Postprocedural retroperitoneal abscess
K68.12 Psoas muscle abscess

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.