K35 — Acute appendicitis
Is K35 billable?
No — K35 is a non-billable header code. K35 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 13 billable codes beneath K35.
Billable codes under this header
- K35.30Acute appendicitis with localized peritonitis, without perforation or gangrene
- K35.31Acute appendicitis with localized peritonitis and gangrene, without perforation
- K35.32Acute appendicitis with perforation, localized peritonitis, and gangrene, without abscess
- K35.33Acute appendicitis with perforation, localized peritonitis, and gangrene, with abscess
- K35.80Unspecified acute appendicitis
- K35.200Acute appendicitis with generalized peritonitis, without perforation or abscess
- K35.201Acute appendicitis with generalized peritonitis, with perforation, without abscess
- K35.209Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation
- K35.210Acute appendicitis with generalized peritonitis, without perforation, with abscess
- K35.211Acute appendicitis with generalized peritonitis, with perforation and abscess
- K35.219Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation
- K35.890Other acute appendicitis without perforation or gangrene
- K35.891Other acute appendicitis without perforation, with gangrene
K35 at a glance
| Code | K35 |
|---|---|
| Description | Acute appendicitis |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes2 — not included here — inherited from Chapter 11
The conditions below are not part of K35, but a patient may have both at the same time. When documentation supports it, K35 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
What codes fall under K35? (3)
How long has K35 existed?
K35 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with K35?
ICD-10-CM declares these codes mutually exclusive with K35 — exactly one of each pair can be correct for a given encounter.