ICD-10 Code I82.521 – Chronic embolism and thrombosis of right iliac vein (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I82.521 – Chronic embolism and thrombosis of right iliac vein
What it is
I82.521 identifies a chronic blockage in the right iliac vein caused by old clot material or embolic obstruction. Use it when documentation specifies the right iliac vein and the condition is chronic, not acute.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include chronic unilateral leg swelling, venous pain, heaviness, or signs of post-thrombotic venous disease.
When to use this code
Use this code when the provider documents chronic embolism or thrombosis involving the right iliac vein. It also fits follow-up encounters for a known chronic clot, provided the record clearly identifies the site and chronicity.
If the note only says venous thrombosis without laterality or chronicity, check documentation before coding. Do not assume the iliac vein or the right side from imaging alone unless the diagnosis is stated.
Do not use for
Do not use I82.521 for acute DVT, unspecified venous thrombosis, or thrombosis in another vein location. Check documentation if the record describes superficial thrombophlebitis or a different vascular disorder.
Coding tip
Match both the anatomic site and the chronic nature of the clot exactly as documented.