ICD-10 Code I77.3 – Arterial fibromuscular dysplasia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I77.3 – Arterial fibromuscular dysplasia
What it is
Arterial fibromuscular dysplasia is a noninflammatory, nonatherosclerotic disease that affects the walls of medium-sized arteries. It can cause narrowing, beading, or abnormal artery shape, most often in renal or carotid vessels.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include arterial stenosis, aneurysm, dissection, or imaging showing the classic “string-of-beads” appearance.
When to use this code
Use this code when the provider documents arterial fibromuscular dysplasia or confirms FMD on imaging or specialist evaluation. It is appropriate when the diagnosis is established, even if the affected artery is not specified in the note. If the record only mentions suspected disease, check documentation before coding.
Do not use for
Do not use this code for atherosclerosis, vasculitis, or other causes of arterial narrowing. If the documentation only states an artery lesion without fibromuscular dysplasia, check documentation.
Coding tip
Code I77.3 only when the provider clearly identifies fibromuscular dysplasia, not just an incidental vascular abnormality.