ICD10BillableValid for clinical use
ICD-10 Code I80.9: Phlebitis and thrombophlebitis of unspecified site
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 circulatory system (I00-I99).
When is it used?
- May be used when a clinician documents phlebitis and thrombophlebitis of unspecified site 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
category
I80Phlebitis and thrombophlebitis
currentI80
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
Related codes
I80.0Phlebitis and thrombophlebitis of superficial vessels of lower extremitiescategoryI80.1Phlebitis and thrombophlebitis of femoral veincategoryI80.2Phlebitis and thrombophlebitis of other and unspecified deep vessels of lower extremitiescategoryI80.3Phlebitis and thrombophlebitis of lower extremities, unspecifiedcodeI80.8Phlebitis and thrombophlebitis of other sitescode
Sibling codes
I80.0Phlebitis and thrombophlebitis of superficial vessels of lower extremitiesI80.1Phlebitis and thrombophlebitis of femoral veinI80.2Phlebitis and thrombophlebitis of other and unspecified deep vessels of lower extremitiesI80.3Phlebitis and thrombophlebitis of lower extremities, unspecifiedbillableI80.8Phlebitis and thrombophlebitis of other sitesbillable
Mapped diagnoses and classifications
SNOMED_CT 16750002high
Deep thrombophlebitis
Source: SNOMED International ICD-10 map
SNOMED_CT 54771008high
Endophlebitis
Source: SNOMED International ICD-10 map
SNOMED_CT 36675003high
Periphlebitis
Source: SNOMED International ICD-10 map
SNOMED_CT 61599003high
Phlebitis
Source: SNOMED International ICD-10 map
SNOMED_CT 439731006high
Septic thrombophlebitis
Source: SNOMED International ICD-10 map
SNOMED_CT 72930009high
Superficial migratory thrombophlebitis
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
I80.9
Common synonyms
Phlebitis and thrombophlebitis of unspecified sitePhlebitis and thrombophlebitis of site
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.