ICD-10 Code I80.239 – Phlebitis and thrombophlebitis of unspecified tibial vein (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I80.239 – Phlebitis and thrombophlebitis of unspecified tibial vein
What it is
I80.239 identifies inflammation and clot formation in a tibial vein of the lower leg when the side is not specified. Use this code when the record confirms tibial vein thrombophlebitis but does not name right or left.
Clinical signs
Typical findings include localized leg pain, tenderness, swelling, warmth, and sometimes redness over the affected calf. Clinical features vary; refer to documentation, and confirm that the provider documents a tibial vein thrombophlebitis diagnosis.
When to use this code
Use I80.239 when documentation states phlebitis or thrombophlebitis of a tibial vein and laterality is not recorded. It also fits when the note identifies the tibial vein as the affected site without specifying whether the condition is acute or chronic in a way that changes coding. Check documentation if the record is unclear.
Do not use for
Do not use this code for superficial thrombophlebitis, deep vein thrombosis in another lower-extremity vein, or when the provider documents a different vein location. If laterality is known, use the specified code instead.
Coding tip
Verify the exact vein and laterality in the note; unspecified codes are appropriate only when the documentation does not identify the side.