K35.209 Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation

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

Applicable to

• (Acute) appendicitis with generalized peritonitis NOS

MS-DRG index

Defines the logic of DRG(s) 371-373 in MDC 06.

Code annotations containing back-references to K35.209

Back-references to K35.2

• Type 1 Excludes: K37 Unspecified appendicitis ("unspecified appendicitis with peritonitis (K35.2-, K35.3-)")
• Type 2 Excludes: K63.1 Perforation of intestine (nontraumatic) ("perforation (nontraumatic) of appendix (K35.2-, K35.3-)")
• Type 1 Excludes: K65 Peritonitis ("acute appendicitis with generalized peritonitis (K35.2-)")

Back-references to K35

• Type 1 Excludes: K65 Peritonitis ("peritonitis with or following appendicitis (K35.-)")

Diagnosis Index entries for K35.209

• Appendicitis (pneumococcal) (retrocecal) › with › peritonitis NEC › generalized
• Appendicitis (pneumococcal) (retrocecal) › acute (catarrhal) (fulminating) (obstructive) (retrocecal) (suppurative) › with › peritonitis NEC › generalized
• Peritonitis (adhesive) (bacterial) (fibrinous) (hemorrhagic) (idiopathic) (localized) (perforative) (primary) (with adhesions) (with effusion) › with or following › appendicitis › generalized

Nearby codes

• K35 Acute appendicitis
• K35.2 Acute appendicitis with generalized peritonitis
• K35.20 Acute appendicitis with generalized peritonitis, without abscess
• K35.200 Acute appendicitis with generalized peritonitis, without perforation or abscess
• K35.201 Acute appendicitis with generalized peritonitis, with perforation, without abscess
• K35.209 Acute appendicitis with generalized peritonitis, without abscess, unspecified as to perforation (this code)
• K35.21 Acute appendicitis with generalized peritonitis, with abscess
• K35.210 Acute appendicitis with generalized peritonitis, without perforation, with abscess
• K35.211 Acute appendicitis with generalized peritonitis, with perforation and abscess
• K35.219 Acute appendicitis with generalized peritonitis, with abscess, unspecified as to perforation
• K35.3 Acute appendicitis with localized peritonitis