K65.1 Peritoneal abscess

Billable ICD-10-CM code, FY2026. Acts as a Major Complication or Comorbidity (MCC) as a secondary diagnosis.

Applicable to

• Abdominopelvic abscess
• Abscess (of) omentum
• Abscess (of) peritoneum
• Mesenteric abscess
• Retrocecal abscess
• Subdiaphragmatic abscess
• Subhepatic abscess
• Subphrenic abscess

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)

• 567.22 Peritoneal abscess

Code annotations containing back-references to K65.1

Back-references to K65

• Code Also: K57 Diverticular disease of intestine ("if applicable peritonitis K65.-")

Diagnosis Index entries for K65.1

• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › abdomen, abdominal › cavity
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › abdominopelvic
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › diaphragm, diaphragmatic
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › epiploon, epiploic
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › intra-abdominal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › intraperitoneal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › mesentery, mesenteric
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › omentum
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › pelvis, pelvic › male, peritoneal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › peritoneum, peritoneal (perforated) (ruptured)
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › peritoneum, peritoneal (perforated) (ruptured) › pelvic › male
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › retrocecal
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › subdiaphragmatic
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › subhepatic
• Abscess (connective tissue) (embolic) (fistulous) (infective) (metastatic) (multiple) (pernicious) (pyogenic) (septic) › subphrenic
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) › with or following › abscess
• Sepsis (generalized) (unspecified organism) › intra-abdominal

Nearby codes

• K65 Peritonitis
• K65.0 Generalized (acute) peritonitis
• K65.1 Peritoneal abscess (this code)
• K65.2 Spontaneous bacterial peritonitis
• K65.3 Choleperitonitis
• K65.4 Sclerosing mesenteritis
• K65.8 Other peritonitis
• K65.9 Peritonitis, unspecified