ICD-10 Code I70.56 – Atherosclerosis of nonautologous biological bypass graft(s) of the extremities with gangrene (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I70.56 – Atherosclerosis of nonautologous biological bypass graft(s) of the extremities with gangrene
What it is
This code identifies atherosclerotic narrowing or blockage in a nonautologous biological bypass graft in an extremity, with tissue death from gangrene. Use it when the graft itself is the affected vessel and gangrene is documented.
Clinical signs
Findings may include a cold, painful limb, poor distal pulses, ischemic skin changes, and black or necrotic tissue consistent with gangrene. Clinical features vary; refer to documentation.
When to use this code
Use I70.56 when the provider documents atherosclerosis in a nonautologous biological bypass graft in the arm or leg and also documents gangrene. The graft may be described as narrowed, occluded, or failing because of atherosclerotic disease. If the note does not clearly identify the graft type or gangrene, check documentation.
Do not use for
Do not use this code for native artery atherosclerosis, nonatherosclerotic graft failure, or gangrene without documented atherosclerosis of the graft. Check documentation if the graft source or site is unclear.
Coding tip
Code the graft-specific diagnosis exactly as documented, and verify that gangrene is present before assigning I70.56.