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ICD-10-CM · FY 2026 APRIL UPDATE

K35

Acute appendicitis

Diagnosis reference

Nonbillable category

This entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.

Effective periodOctober 1, 2026–September 30, 2027
SourceCMS ICD-10-CM order file
ClassificationDiagnosis · clinical modification

Related entries

Up to 30 descendants in this category

CODEDESCRIPTIONTYPE
K35.2Acute appendicitis with generalized peritonitisCategory
K35.20Acute appendicitis with generalized peritonitis, without abscessCategory
K35.200Acute appendicitis with generalized peritonitis, without perforation or abscessBillable
K35.201Acute appendicitis with generalized peritonitis, with perforation, without abscessBillable
K35.209Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforationBillable
K35.21Acute appendicitis with generalized peritonitis, with abscessCategory
K35.210Acute appendicitis with generalized peritonitis, without perforation, with abscessBillable
K35.211Acute appendicitis with generalized peritonitis, with perforation and abscessBillable
K35.219Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforationBillable
K35.3Acute appendicitis with localized peritonitisCategory
K35.30Acute appendicitis with localized peritonitis, without perforation or gangreneBillable
K35.31Acute appendicitis with localized peritonitis and gangrene, without perforationBillable
K35.32Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscessBillable
K35.33Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscessBillable
K35.8Other and unspecified acute appendicitisCategory
K35.80Unspecified acute appendicitisBillable
K35.89Other acute appendicitisCategory
K35.890Other acute appendicitis without perforation or gangreneBillable
K35.891Other acute appendicitis without perforation, with gangreneBillable

Use the complete reference

This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.

Open official CMS files

ICD-10-CM codes describe diagnoses. They do not have an independent Medicare PFS reimbursement amount, and billability alone does not establish coverage.