ICD-10-CM K65: Peritonitis

ICD-10-CM Diagnosis Code (2025)

Official Description for K65

Peritonitis

Coding Notes & Guidelines for K65

Excludes1: Not Coded Here
  • 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.-)
Excludes1: Not Coded Here

bacterial peritonitis NOS (K65.9)

Use Additional Code

code (B95-B97), to identify infectious agent, if known

Inclusion Terms
  • Pelvic peritonitis (acute), male
  • Subphrenic peritonitis (acute)
  • Suppurative peritonitis (acute)
Inclusion Terms
  • Abdominopelvic abscess
  • Abscess (of) omentum
  • Abscess (of) peritoneum
  • Mesenteric abscess
  • Retrocecal abscess
  • Subdiaphragmatic abscess
  • Subhepatic abscess
  • Subphrenic abscess
Inclusion Terms

Peritonitis due to bile

Inclusion Terms
  • Fat necrosis of peritoneum
  • (Idiopathic) sclerosing mesenteric fibrosis
  • Mesenteric lipodystrophy
  • Mesenteric panniculitis
  • Retractile mesenteritis
Inclusion Terms
  • Chronic proliferative peritonitis
  • Peritonitis due to urine
Inclusion Terms

Bacterial peritonitis NOS

Code Also

if applicable diverticular disease of intestine (K57.-)

Child Codes (More Specific Codes for K65):

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

About ICD-10-CM Code K65 (Peritonitis)

ICD-10-CM code K65 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM K65 became effective on October 1, 2024.

This page provides detailed information about K65 - Peritonitis. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Peritonitis.