ICD10BillableValid for clinical use

ICD-10 Code K35.201: Acute appendicitis with generalized peritonitis, with perforation, without abscess

K35.201 is a billable ICD-10 diagnosis code used to classify Acute appendicitis with generalized peritonitis, with perforation, without abscess in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the digestive system (K00-K95).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the digestive system (K00-K95).

When is it used?

  • May be used when a clinician documents acute appendicitis with generalized peritonitis, with perforation, without abscess in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
11Diseases of the digestive system (K00-K95)
block
K35-K38Diseases of appendix
category
K35Acute appendicitis
category
K35.2Acute appendicitis with generalized peritonitis
category
K35.20Acute appendicitis with generalized peritonitis, without abscess
currentK35.20

Official coding notes

Inclusion terms
  • Appendicitis (acute) with generalized (diffuse) peritonitis following rupture or perforation of appendix NOS

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

GastroenterologistGeneral Physician

Coverage-related procedures and services

CPT 87505high
INFECTIOUS AGENT DETECTION BY NUCLEIC ACID (DNA OR RNA); GASTROINTESTINAL PATHOGEN (EG, CLOSTRIDIUM DIFFICILE, E. COLI, SALMONELLA, SHIGELLA, NOROVIRUS, GIARDIA), INCLUDES MULTIPLEX REVERSE TRANSCRIPTION, WHEN PERFORMED, AND MULTIPLEX AMPLIFIED PROBE TECHNIQUE, MULTIPLE TYPES OR SUBTYPES, 3-5 TARGETS
Source: CMS coverage guidance
CPT 74177high
COMPUTED TOMOGRAPHY, ABDOMEN AND PELVIS; WITH CONTRAST MATERIAL(S)
Source: CMS coverage guidance
CPT 74176high
COMPUTED TOMOGRAPHY, ABDOMEN AND PELVIS; WITHOUT CONTRAST MATERIAL
Source: CMS coverage guidance
CPT 74178high
COMPUTED TOMOGRAPHY, ABDOMEN AND PELVIS; WITHOUT CONTRAST MATERIAL IN ONE OR BOTH BODY REGIONS, FOLLOWED BY CONTRAST MATERIAL(S) AND FURTHER SECTIONS IN ONE OR BOTH BODY REGIONS
Source: CMS coverage guidance
CPT 74160high
COMPUTED TOMOGRAPHY, ABDOMEN; WITH CONTRAST MATERIAL(S)
Source: CMS coverage guidance
CPT 74150high
COMPUTED TOMOGRAPHY, ABDOMEN; WITHOUT CONTRAST MATERIAL
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Acute appendicitis with generalized peritonitis, with perforation, without abscess

Frequently asked questions

Code details

CodeK35.201
SystemICD10
Display nameAcute appendicitis with generalized peritonitis, with perforation, without abscess
ChapterDiseases of the digestive system (K00-K95)
BlockDiseases of appendix

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Appendicitis(pneumococcal) (retrocecal)Appendicitis(pneumococcal) (retrocecal)Appendicitis(pneumococcal) (retrocecal)Appendicitis(pneumococcal) (retrocecal)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code K35.201 for Acute appendicitis with generalized peritonitis, with perforation, without abscess | HealthAssure