ICD-10 Code I80.0 – Phlebitis and thrombophlebitis of superficial vessels of lower extremities (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I80.0 – Phlebitis and thrombophlebitis of superficial vessels of lower extremities
What it is
I80.0 identifies inflammation and clotting in the superficial veins of the lower leg or thigh. Use it for superficial venous thrombophlebitis, not deep vein thrombosis.
Clinical signs
Typical findings include a tender, warm, red, cordlike vein along the leg. Clinical features vary; refer to documentation for laterality, extent, and whether the process is acute or recurrent.
When to use this code
Use this code when the provider documents phlebitis or thrombophlebitis in a superficial vein of the lower extremity. It also fits documented superficial venous inflammation with associated thrombus in the leg. If the note only says “leg swelling” or “varicose veins,” check documentation before assigning I80.0.
Do not use for
Do not use I80.0 for deep vein thrombosis or for superficial thrombophlebitis in sites outside the lower extremities. Do not code it from nonspecific pain or redness alone.
Coding tip
Code from the provider’s documented vein location and avoid substituting this code for unspecified venous disease.