K65.9 ICD-10-CA code: Peritonitis, unspecified
K65.9 is the ICD-10-CA code for “Peritonitis, unspecified” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
K65.9Peritonitis, unspecified
Short description: Peritonitis unspecified
ICD-10-CA · Canada · Also written K659
Index terms
Entries in CIHI’s alphabetical index that lead to K65.9. Searching the index by the condition the note names is how coders reach this code.
- Omentitis
- Epiploitis
- Mesenteritis
- Retroperitonitis
- Fistula, peritoneum
- Hemoperitoneum, infectional
- Infection, infected (opportunistic), peritoneal
- Peritonitis (adhesive) (fibrinous) (with effusion)
- Inflammation, inflamed, inflammatory (with exudation), peritoneum
- Inflammation, inflamed, inflammatory (with exudation), retroperitoneal
Notes for K65.9
As CIHI prints them, with any note K65.9 takes from the headings above it.
Excludes
Conditions classified elsewhere.
- Peritonitis:• aseptic (T81.6)• benign paroxysmal (E85.0)• chemical (T81.6)• due to talc or other foreign substance (T81.6)• neonatal (P78.0-P78.1)• pelvic, female (N73.3-N73.5)• periodic familial (E85.0)• puerperal (O85)• with or following• abortion or ectopic or molar pregnancy (O00-O07,O08.0)• appendicitis (K35.-)• diverticular disease of intestine (K57.-)From K65 Peritonitis
- Certain:• conditions originating in the perinatal period (P00-P96)• infectious and parasitic diseases (A00-B99)complications of pregnancy, childbirth and the puerperium (O00-O99)congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)endocrine, nutritional and metabolic diseases (E00-E90)injury, poisoning and certain other consequences of external causes (S00-T98)neoplasms (C00-D48)symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)From Chapter 11: Diseases of the digestive system (K00-K93)
Where K65.9 sits
- 1ChapterChapter 11: Diseases of the digestive system (K00-K93)
- 2Block K65-K67Diseases of peritoneum
- 3Category K65Peritonitis
- 4Valid code K65.9Peritonitis, unspecified
Source and release
- Data release
- ICD-10-CA · FY 2026–2027
- Effective date
- Apr 1, 2026
- Publisher
- CIHI
This page is built from the ICD-10-CA catalog that Vero Codes reads when it suggests codes: Canadian Institute for Health Information’s FY 2026–2027 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does ICD-10-CA code K65.9 mean?
K65.9 is the ICD-10-CA code for “Peritonitis, unspecified” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is K65.9 in ICD-10-CA?
K65.9 sits under K65 Peritonitis, within K65-K67 Diseases of peritoneum, within Chapter 11: Diseases of the digestive system (K00-K93).
What coding notes apply to K65.9?
ICD-10-CA lists Excludes notes for K65.9, including those from the headings it sits under. They are listed on this page with where each one comes from.
Which ICD-10-CA release does this page use?
It uses CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026 to Mar 31, 2027. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.