ICD10BillableValid for clinical use
ICD-10 Code K66.9: Disorder of peritoneum, unspecified
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 disorder of peritoneum, unspecified 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
K65-K68Diseases of peritoneum and retroperitoneum
category
K66Other disorders of peritoneum
currentK66
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
Related codes
Sibling codes
Coverage-related procedures and services
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
CPT 74170high
COMPUTED TOMOGRAPHY, ABDOMEN; WITHOUT CONTRAST MATERIAL, FOLLOWED BY CONTRAST MATERIAL(S) AND FURTHER SECTIONS
Source: CMS coverage guidance
Mapped diagnoses and classifications
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
K66.9
Common synonyms
Disorder of peritoneum, unspecifiedDisorder of peritoneum
Frequently asked questions
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.