ICD-10 Code I70.599 – Other atherosclerosis of nonautologous biological bypass graft(s) of the extremities, unspecified extremity (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I70.599 – Other atherosclerosis of nonautologous biological bypass graft(s) of the extremities, unspecified extremity
What it is
This code identifies atherosclerotic disease affecting a nonautologous biological bypass graft in an extremity when the affected limb is not specified. It reflects plaque-related narrowing or blockage in a graft used to route blood around diseased vessels.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records may describe reduced graft patency, limb ischemia, diminished pulses, pain with walking, or signs of poor perfusion in the involved extremity.
When to use this code
Use this code when the provider documents atherosclerosis in a nonautologous biological bypass graft of an arm or leg and does not specify the extremity. It is appropriate for graft-related arterial disease, not for native vessel atherosclerosis alone. If the note identifies a specific limb, code that laterality instead.
Do not use for
Do not use this code for atherosclerosis of native arteries, graft occlusion without atherosclerosis, or complications not documented as atherosclerotic disease. Check documentation if the graft type or affected extremity is unclear.
Coding tip
Assign I70.599 only when the record clearly links atherosclerosis to a nonautologous biological bypass graft and leaves the extremity unspecified.