K35.21
Acute appendicitis with generalized peritonitis, with abscess
Non-billable headerNot valid on its own. Use one of the more specific codes under it.
K35.21 is a non-billable ICD-10-CM code header for acute appendicitis with generalized peritonitis, with abscess. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are K35.210 Acute appendicitis with generalized peritonitis, without perforation, with abscess; K35.211 Acute appendicitis with generalized peritonitis, with perforation and abscess and K35.219 Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation. Its coding notes include 8 Excludes2 entries.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
Inherited from Chapter 11 Diseases of the digestive system
- 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)