ICD-10 Code I82.559 – Chronic embolism and thrombosis of unspecified peroneal vein (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I82.559 – Chronic embolism and thrombosis of unspecified peroneal vein
What it is
This code identifies a chronic blood clot or embolic blockage in a peroneal vein when the affected side is not documented. Use it for an ongoing, not acute, venous obstruction in the lower leg.
Clinical signs
Clinical features vary; refer to documentation. Commonly, venous thrombosis may be noted with leg swelling, pain, tenderness, or heaviness, but the diagnosis should be supported by imaging or other documented assessment.
When to use this code
Use this code when the record clearly states chronic embolism and thrombosis involving a peroneal vein and does not specify right or left. It is appropriate for follow-up documentation of a persistent or old clot, not a new acute event. If the side is documented, select the more specific code.
Do not use for
Do not use this code for acute deep vein thrombosis, superficial thrombophlebitis, or thrombosis in a different vein location. Check documentation if the record does not clearly state chronicity or the involved side.
Coding tip
Verify both chronic status and laterality; if either is missing, query the provider or code to the documented specificity.