ICD-10 Code I70.643 – Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of ankle (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I70.643 – Atherosclerosis of nonbiological bypass graft(s) of the left leg with ulceration of ankle
What it is
This code identifies atherosclerotic narrowing or blockage in a nonbiological bypass graft in the left leg, with an associated ankle ulcer. Use it when the graft disease and ulcer are both documented.
Clinical signs
Findings may include reduced blood flow through the graft, poor wound healing, and an ulcer at the ankle. Clinical features vary; refer to documentation for laterality, graft type, and ulcer presence.
When to use this code
Use I70.643 when the provider documents atherosclerosis affecting a nonbiological bypass graft in the left leg and specifically links it to an ankle ulcer. The record should support the graft site, left-sided location, and ulceration. Check documentation if the ulcer site is unclear or if the graft is not nonbiological.
Do not use for
Do not use this code for native artery atherosclerosis, right leg disease, or bypass grafts without ulceration. Also avoid it when the ulcer is elsewhere or the graft material is not documented.
Coding tip
Verify that the ulcer location is the ankle and that the bypass graft is nonbiological before assigning this code.