K65
Peritonitis
K65 is a non-billable ICD-10-CM code category for peritonitis. 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 K65.0 Generalized (acute) peritonitis, K65.1 Peritoneal abscess, K65.2 Spontaneous bacterial peritonitis, K65.3 Choleperitonitis and 3 more. Its coding notes include a Use additional code instruction, a Code also instruction, 17 Excludes1 entries and 8 Excludes2 entries.
Use additional code
Add the listed code as a secondary code, if known.
- code (B95-B97), to identify infectious agent, if known
Code also
Two codes may be needed to describe the condition. This note gives no sequencing order.
- if applicable diverticular disease of intestine (K57.-)
Excludes1
Not coded here. The listed conditions generally should not be reported together.
- acute appendicitis with generalized peritonitis (K35.2-)
- aseptic peritonitis (T81.6)
- benign paroxysmal peritonitis (E85.0)
- chemical peritonitis (T81.6)
- gonococcal peritonitis (A54.85)
- neonatal peritonitis (P78.0-P78.1)
- pelvic peritonitis, female (N73.3-N73.5)
- periodic familial peritonitis (E85.0)
- peritonitis due to talc or other foreign substance (T81.6)
- peritonitis in chlamydia (A74.81)
- peritonitis in diphtheria (A36.89)
- peritonitis in syphilis (late) (A52.74)
- peritonitis in tuberculosis (A18.31)
- peritonitis with or following abortion or ectopic or molar pregnancy (O00-O07, O08.0)
- peritonitis with or following appendicitis (K35.-)
- puerperal peritonitis (O85)
- retroperitoneal infections (K68.-)
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (8 notes)
- 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)