ICD-10 Code I80.242 – Phlebitis and thrombophlebitis of left peroneal vein (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I80.242 – Phlebitis and thrombophlebitis of left peroneal vein
What it is
This code identifies inflammation and clot formation in the left peroneal vein, a deep vein in the lower leg. Use it when documentation specifically states phlebitis or thrombophlebitis in that vein.
Clinical signs
Typical findings include unilateral leg pain, swelling, warmth, tenderness, or redness, though clinical features vary; refer to documentation. Diagnosis is usually supported by imaging or a clear provider statement.
When to use this code
Use I80.242 when the record documents left peroneal vein thrombophlebitis or phlebitis, including acute or specified deep vein involvement. Apply it only when the provider names the left peroneal vein as the site. If the note only says DVT or lower-extremity thrombosis, check documentation for the exact vein.
Do not use for
Do not use this code for superficial thrombophlebitis, unspecified leg DVT, or thrombosis in another vein. Check documentation when the side, vein, or acute status is not clearly stated.
Coding tip
Confirm the documented vein and laterality before assigning I80.242.