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ICD10BillableValid for clinical use

ICD-10 Code I81: Portal vein thrombosis

I81 is a billable ICD-10 diagnosis code used to classify Portal vein thrombosis 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 circulatory system (I00-I99).

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 circulatory system (I00-I99).

When is it used?

  • May be used when a clinician documents portal vein thrombosis 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
9Diseases of the circulatory system (I00-I99)
block
I80-I89Diseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified
currentI80-I89

Official coding notes

Inclusion terms
  • Portal (vein) obstruction
Excludes2 (may code together if documented)
  • hepatic vein thrombosis (I82.0)
  • phlebitis of portal vein (K75.1)

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

CardiologistGeneral Physician

Coverage-related procedures and services

CPT 93975high
DUPLEX SCAN OF ARTERIAL INFLOW AND VENOUS OUTFLOW OF ABDOMINAL, PELVIC, SCROTAL CONTENTS AND/OR RETROPERITONEAL ORGANS; COMPLETE STUDY
Source: CMS coverage guidance
CPT 93976high
DUPLEX SCAN OF ARTERIAL INFLOW AND VENOUS OUTFLOW OF ABDOMINAL, PELVIC, SCROTAL CONTENTS AND/OR RETROPERITONEAL ORGANS; LIMITED STUDY
Source: CMS coverage guidance
CPT 93978high
DUPLEX SCAN OF AORTA, INFERIOR VENA CAVA, ILIAC VASCULATURE, OR BYPASS GRAFTS; COMPLETE STUDY
Source: CMS coverage guidance
CPT 93979high
DUPLEX SCAN OF AORTA, INFERIOR VENA CAVA, ILIAC VASCULATURE, OR BYPASS GRAFTS; UNILATERAL OR LIMITED STUDY
Source: CMS coverage guidance
CPT 88182high
FLOW CYTOMETRY, CELL CYCLE OR DNA ANALYSIS
Source: CMS coverage guidance
CPT 88185high
FLOW CYTOMETRY, CELL SURFACE, CYTOPLASMIC, OR NUCLEAR MARKER, TECHNICAL COMPONENT ONLY; EACH ADDITIONAL MARKER (LIST SEPARATELY IN ADDITION TO CODE FOR FIRST MARKER)
Source: CMS coverage guidance

Coding guidelines

Compatibility

Legacy and official ICD code match exactly.
Legacy codes
I81

Common synonyms

Portal vein thrombosis

Frequently asked questions

Code details

CodeI81
SystemICD10
Display namePortal vein thrombosis
ChapterDiseases of the circulatory system (I00-I99)
BlockDiseases of veins, lymphatic vessels and lymph nodes, not elsewhere classified

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Block, blockedEmbolism(multiple) (paradoxical)Obstruction, obstructed, obstructivePseudoangiomaThrombosis, thrombotic(bland) (multiple) (progressive) (silent) (vessel)Thrombosis, thrombotic(bland) (multiple) (progressive) (silent) (vessel)

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.