ICD-10 Code I70.503 – Unspecified atherosclerosis of nonautologous biological bypass graft(s) of the extremities, bilateral legs (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I70.503 – Unspecified atherosclerosis of nonautologous biological bypass graft(s) of the extremities, bilateral legs
What it is
This code identifies atherosclerotic disease affecting nonautologous biological bypass grafts in both lower extremities, when the documentation does not specify further detail. Use it for graft-related plaque buildup or narrowing in bilateral leg bypass vessels.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include reduced graft patency, diminished distal pulses, limb ischemic symptoms, or evidence of graft stenosis on imaging or vascular evaluation.
When to use this code
Use this code when the provider documents atherosclerosis involving a nonautologous biological bypass graft in both legs and does not name a more specific subtype. It is appropriate when the record supports bilateral lower-extremity graft disease but lacks details such as graft complication type or severity.
Check documentation if the note describes native artery disease, an autologous vein graft, or a prosthetic graft instead. Also verify laterality; this code is specific to bilateral legs.
Do not use for
Do not use this code for atherosclerosis of native leg arteries, unilateral graft disease, or graft occlusion without documented atherosclerosis. Check documentation when the graft type is not clearly nonautologous biological.
Coding tip
Confirm both the graft type and bilateral leg involvement in the operative note or vascular report before assigning I70.503.