K65.9 Peritonitis, unspecified
Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.
Applicable to
- Bacterial peritonitis NOS
Applies from K65 Peritonitis
Excludes1 (never code 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.-)
Use additional code
- code (B95-B97), to identify infectious agent, if known
Code also
- if applicable diverticular disease of intestine (K57.-)
Risk adjustment (HCC)
- CMS-HCC V28: HCC 78 — Intestinal Obstruction/Perforation
- CMS-HCC V22: HCC 33 — Intestinal Obstruction/Perforation
- ESRD V24: HCC 33
MS-DRG index
Defines the logic of DRG(s) 371-373 in MDC 06.
Approximate ICD-9-CM (GEMs)
567.9 Unspecified peritonitis
Code annotations containing back-references to K65.9
Back-references to K65.9
- Type 1 Excludes:
K65.2 Spontaneous bacterial peritonitis ("bacterial peritonitis NOS (K65.9)")
Back-references to K65
- Code Also:
K57 Diverticular disease of intestine ("if applicable peritonitis K65.-")
Diagnosis Index entries for K65.9
- Fistula (cutaneous) › peritoneum
- Hemoperitoneum › infectional
- Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion)
Nearby codes
K65.1 Peritoneal abscessK65.2 Spontaneous bacterial peritonitisK65.3 CholeperitonitisK65.4 Sclerosing mesenteritisK65.8 Other peritonitisK65.9 Peritonitis, unspecified (this code)