K35: Acute appendicitis
Codes under K35 (Acute appendicitis). A ✓ marks a billable (fully specified) code; category codes without a ✓ are not billable on their own.
| Code | Description | Billable |
|---|---|---|
| K35.2 | Acute appendicitis with generalized peritonitis | — |
| K35.2 | Acute appendicitis with generalized peritonitis | — |
| K35.3 | Acute appendicitis with localized peritonitis | — |
| K35.3 | Acute appendicitis with localized peritonitis | — |
| K35.8 | Other and unspecified acute appendicitis | — |
| K35.8 | Other and unspecified acute appendicitis | — |
| K35.20 | Acute appendicitis with generalized peritonitis, without abscess | — |
| K35.20 | Acute appendicitis with generalized peritonitis, without abscess | — |
| K35.21 | Acute appendicitis with generalized peritonitis, with abscess | — |
| K35.21 | Acute appendicitis with generalized peritonitis, with abscess | — |
| K35.30 | Acute appendicitis with localized peritonitis, without perforation or gangrene | ✓ |
| K35.30 | Acute appendicitis with localized peritonitis, without perforation or gangrene | ✓ |
| K35.31 | Acute appendicitis with localized peritonitis and gangrene, without perforation | ✓ |
| K35.31 | Acute appendicitis with localized peritonitis and gangrene, without perforation | ✓ |
| K35.32 | Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess | ✓ |
| K35.32 | Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess | ✓ |
| K35.33 | Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess | ✓ |
| K35.33 | Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess | ✓ |
| K35.80 | Unspecified acute appendicitis | ✓ |
| K35.80 | Unspecified acute appendicitis | ✓ |
| K35.89 | Other acute appendicitis | — |
| K35.89 | Other acute appendicitis | — |
| K35.200 | Acute appendicitis with generalized peritonitis, without perforation or abscess | ✓ |
| K35.200 | Acute appendicitis with generalized peritonitis, without perforation or abscess | ✓ |
| K35.201 | Acute appendicitis with generalized peritonitis, with perforation, without abscess | ✓ |
| K35.201 | Acute appendicitis with generalized peritonitis, with perforation, without abscess | ✓ |
| K35.209 | Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation | ✓ |
| K35.209 | Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation | ✓ |
| K35.210 | Acute appendicitis with generalized peritonitis, without perforation, with abscess | ✓ |
| K35.210 | Acute appendicitis with generalized peritonitis, without perforation, with abscess | ✓ |
| K35.211 | Acute appendicitis with generalized peritonitis, with perforation and abscess | ✓ |
| K35.211 | Acute appendicitis with generalized peritonitis, with perforation and abscess | ✓ |
| K35.219 | Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation | ✓ |
| K35.219 | Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation | ✓ |
| K35.890 | Other acute appendicitis without perforation or gangrene | ✓ |
| K35.890 | Other acute appendicitis without perforation or gangrene | ✓ |
| K35.891 | Other acute appendicitis without perforation, with gangrene | ✓ |
| K35.891 | Other acute appendicitis without perforation, with gangrene | ✓ |
Frequently asked questions
What is ICD-10-CM code K35?
K35 is an ICD-10-CM category covering Acute appendicitis. It contains 38 more specific diagnosis codes, 26 of which are billable.
Is K35 a billable code?
No — K35 is a category header and isn't billable on its own. Code to the highest level of specificity using one of its subcodes (for example K35.2 — Acute appendicitis with generalized peritonitis). 26 of the 38 codes under K35 are billable.
What codes fall under K35?
K35 includes K35.2, K35.2, K35.3, K35.3, K35.8, plus 33 more. See the full list with descriptions and billable status above.
More free billing tools: all ICD-10 categories · ICD-10 search · denial codes · Medicare fees
Informational only, not coding or medical advice. Verify against the official ICD-10-CM (FY2026) and your payer's guidelines.
Code the diagnosis right
Join providers across the country delivering modern virtual care with CareNiva. Free to start, ready in minutes.
100% Satisfaction Guaranteed — try it risk-free