K35.3 ICD-10-CA code: Acute appendicitis with localized peritonitis
K35.3 is the ICD-10-CA code for “Acute appendicitis with localized peritonitis” in CIHI’s FY 2026–2027 release, in effect from Apr 1, 2026.
Official description
K35.3Acute appendicitis with localized peritonitis
Short description: Acute appendcts w local peritonitis
ICD-10-CA · Canada · Also written K353
Index terms
Entries in CIHI’s alphabetical index that lead to K35.3. Searching the index by the condition the note names is how coders reach this code.
- Rupture, ruptured, appendix
- Appendicitis, with, peritonitis NEC
- Appendicitis, with, peritoneal abscess
- Appendicitis, with, perforation or rupture NEC
- Perforation, perforated (nontraumatic), appendix
- Rupture, ruptured, appendix, with peritonitis, localized
- Appendicitis, with, peritonitis NEC, localized (with perforation or rupture)
- Perforation, perforated (nontraumatic), appendix, with peritonitis, localized
- Gangrene, gangrenous (dry) (moist) (skin) (ulcer), appendix, with, peritonitis NEC
- Abscess (embolic) (infective) (metastatic) (multiple) (pyogenic) (septic), appendix
- Peritonitis (adhesive) (fibrinous) (with effusion), with or following, appendicitis
- Abscess (embolic) (infective) (metastatic) (multiple) (pyogenic) (septic), ileocecal
- Gangrene, gangrenous (dry) (moist) (skin) (ulcer), appendix, with, peritoneal abscess
- Abscess (embolic) (infective) (metastatic) (multiple) (pyogenic) (septic), periappendicular
- Abscess (embolic) (infective) (metastatic) (multiple) (pyogenic) (septic), vermiform appendix
- Appendicitis, acute (catarrhal) (fulminating) (gangrenous) (obstructive) (retrocecal) (suppurative), with, peritonitis NEC
- Gangrene, gangrenous (dry) (moist) (skin) (ulcer), appendix, with, peritonitis NEC, localized (with perforation or rupture)
- Appendicitis, acute (catarrhal) (fulminating) (gangrenous) (obstructive) (retrocecal) (suppurative), with, peritoneal abscess
- Peritonitis (adhesive) (fibrinous) (with effusion), localized, with or following appendicitis (acute) (perforation) (rupture)
- Appendicitis, acute (catarrhal) (fulminating) (gangrenous) (obstructive) (retrocecal) (suppurative), with, perforation or rupture NEC
- Abscess (embolic) (infective) (metastatic) (multiple) (pyogenic) (septic), peritoneum, peritoneal (perforated) (ruptured), with appendicitis
- Appendicitis, acute (catarrhal) (fulminating) (gangrenous) (obstructive) (retrocecal) (suppurative), with, peritonitis NEC, localized (with perforation or rupture)
Notes for K35.3
As CIHI prints them, with any note K35.3 takes from the headings above it.
Includes
- Acute appendicitis (with or without perforation or rupture) with peritonitis:• NOS• localizedAcute appendicitis with peritoneal abscess
Excludes
Conditions classified elsewhere.
- 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 K35.3 sits
- 1ChapterChapter 11: Diseases of the digestive system (K00-K93)
- 2Block K35-K38Diseases of appendix
- 3Category K35Acute appendicitis
- 4Valid code K35.3Acute appendicitis with localized peritonitis
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 K35.3 mean?
K35.3 is the ICD-10-CA code for “Acute appendicitis with localized peritonitis” in CIHI’s ICD-10-CA FY 2026–2027 release.
Where is K35.3 in ICD-10-CA?
K35.3 sits under K35 Acute appendicitis, within K35-K38 Diseases of appendix, within Chapter 11: Diseases of the digestive system (K00-K93).
What coding notes apply to K35.3?
ICD-10-CA lists Includes, Excludes notes for K35.3, 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.