K65.9
BillablePeritonitis, unspecified
Peritonitis, unspecified
Coding Notes
Inclusion Terms
Alternative clinical terms for this condition
- Bacterial peritonitis NOS
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
- •acute appendicitis with generalized peritonitisK35.2
- •aseptic peritonitisT81.6
- •benign paroxysmal peritonitisE85.0
- •chemical peritonitisT81.6
- •gonococcal peritonitisA54.85
- •neonatal peritonitisP78.0-P78.1
- •pelvic peritonitis, femaleN73.3-N73.5
- •periodic familial peritonitisE85.0
- •peritonitis due to talc or other foreign substanceT81.6
- •peritonitis in chlamydiaA74.81
- •peritonitis in diphtheriaA36.89
- •peritonitis in syphilis (late)A52.74
- •peritonitis in tuberculosisA18.31
- •peritonitis with or following abortion or ectopic or molar pregnancy,O00-O07, O08.0
- •peritonitis with or following appendicitisK35
- •puerperal peritonitisO85
- •retroperitoneal infectionsK68
Excludes 2
Conditions not included here, but the patient may have both
- •certain conditions originating in the perinatal periodP04-P96
- •certain infectious and parasitic diseasesA00-B99
- •complications of pregnancy, childbirth and the puerperiumO9A)O00
- •congenital malformations, deformations and chromosomal abnormalitiesQ00-Q99
- •endocrine, nutritional and metabolic diseasesE00-E88
- •injury, poisoning and certain other consequences of external causesS00-T88
- •neoplasmsC00-D49
- •symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classifiedR00-R94
Use Additional Code
Additional codes that should follow this code
Code Also
A second code may be required; sequencing depends on circumstances
Related Codes(6)
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(60)
SNOMED CT
- Peritonitis48661000
- Fibrinous peritonitis48819008
- Pneumococcal peritonitis58710009
- Fat necrosis of peritoneum111368002
- Peritoneal fat necrosis111368002
- Infectious peritonitis129129003
- Bacterial peritonitis197171003
- Aseptic peritonitis213293008
- Sterile peritonitis213293008
- Mesenteric fat necrosis236008004
- Ventriculoperitoneal shunt-associated peritonitis277783004
- Serositis370469003
- Peritonitis after surgery427883005
- Postoperative peritonitis427883005
- Mesenteric peritonitis722874004
- Mesenteric peritonitis co-occurrent and due to mesenteric fat necrosis722874004
- Mesenteric peritonitis with mesenteric fat necrosis722874004
- Primary peritonitis735592003
- Acute infective localised peritonitis838354003
- Acute infective localized peritonitis838354003
- Acute localized peritonitis caused by infection838354003
- Acute infectious peritonitis1163087003
UMLS
- Acute bacterial peritonitisC0275550
- Acute bacterial peritonitis (disorder)C0275550
- Bacterial peritonitis NOSC0275550
- Inflammation of the peritoneumC0031154
- Peritoneal inflammationC0031154
- PeritonitisC0031154
- Peritonitis (disorder)C0031154
- Peritonitis, unspecifiedC0031154
- Unspecified peritonitisC0031154
- peritonitisC0031154
Clinical Terms
- Mesenteric peritonitis with mesenteric fat necrosis
- Inflammation of the peritoneum
- Pneumococcal peritonitis
- Acute infective localised peritonitis
- Acute infectious peritonitis
- Ventriculoperitoneal shunt-associated peritonitis
- Fat necrosis of peritoneum
- Primary peritonitis
- Acute infective localized peritonitis
- Acute bacterial peritonitis
- Peritoneal fat necrosis
- Mesenteric fat necrosis
- Acute localized peritonitis caused by infection
- Acute bacterial peritonitis (disorder)
- Sterile peritonitis
- Serositis
- Fibrinous peritonitis
- Bacterial peritonitis NOS
- Peritoneal inflammation
- Postoperative peritonitis
- Mesenteric peritonitis
- Peritonitis after surgery
- Aseptic peritonitis
- Infectious peritonitis
- Mesenteric peritonitis co-occurrent and due to mesenteric fat necrosis
- Peritonitis (disorder)
- Unspecified peritonitis
- Bacterial peritonitis
Frequently Asked Questions
What is the ICD-10 code for peritonitis, unspecified?
The ICD-10-CM code for peritonitis, unspecified is K65.9. The full clinical description is "Peritonitis, unspecified". K65.9 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code K65.9 mean?
ICD-10-CM code K65.9 represents “Peritonitis, unspecified”. It is classified under Chapter 11: Diseases of the Digestive System and is a billable/specific code that can be used on a claim.
Is K65.9 a billable code?
Yes, K65.9 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is K65.9 in?
K65.9 is in Chapter 11: Diseases of the Digestive System (codes K00-K95).
What codes cannot be used with K65.9?
K65.9 has Excludes1 notes indicating codes that cannot be used together with it, including: acute appendicitis with generalized peritonitis (K35.2-); aseptic peritonitis (T81.6); benign paroxysmal peritonitis (E85.0); and 14 more.
Are additional codes required with K65.9?
Yes, when using K65.9, also report: code (B95-B97), to identify infectious agent, if known.
What SNOMED CT codes does K65.9 map to?
K65.9 maps to 15 SNOMED CT concepts: 1163087003, 838354003, 213293008, 197171003, 111368002, and 10 more. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for K65.9?
K65.9 is linked to 2 UMLS Concept Unique Identifiers: C0275550, C0031154. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does K65.9 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like peritonitis, unspecified affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of K65.9?
K65.9 maps to the ICD-11 code: DC50.Z (Peritonitis, unspecified).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.