ICD-10 Code I80.00 – Phlebitis and thrombophlebitis of superficial vessels of unspecified lower extremity (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I80.00 – Phlebitis and thrombophlebitis of superficial vessels of unspecified lower extremity
What it is
I80.00 identifies inflammation and clotting in a superficial vein of the lower leg or thigh when the specific side is not documented. Use it when the record confirms superficial thrombophlebitis but does not specify laterality.
Clinical signs
Typical findings include localized pain, tenderness, redness, warmth, and a palpable cord along a superficial vein. Clinical features vary; refer to documentation for the exact vessel involved and whether the condition is acute or chronic.
When to use this code
Use this code when the provider documents superficial thrombophlebitis or phlebitis of a lower-extremity superficial vessel and does not state right or left. It is also appropriate when the note confirms the diagnosis but laterality remains unspecified. Check documentation if the vein is deep, because that requires a different code.
Do not use for
Do not use I80.00 for deep vein thrombosis, septic thrombophlebitis, or upper-extremity superficial thrombophlebitis. If the record names a specific leg side, code the laterality documented instead.
Coding tip
Before assigning I80.00, verify that the provider documented a superficial vessel and that no laterality was recorded.