ICD-10 Code H34.21 – Partial retinal artery occlusion (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H34.21 – Partial retinal artery occlusion
What it is
H34.21 identifies a partial blockage of a retinal artery, reducing blood flow to part of the retina. It describes an ischemic eye condition that can affect vision and needs prompt clinical evaluation.
Clinical signs
Typical findings include sudden, painless visual loss or a visual field defect in one eye. Funduscopic findings may show retinal ischemia or arterial narrowing; clinical features vary, so refer to documentation.
When to use this code
Use H34.21 when the provider documents partial retinal artery occlusion, including cases described as incomplete arterial blockage of the retina. You may also use it when the diagnosis is confirmed by ophthalmic examination or imaging notes. If the record only says retinal ischemia or vision loss without a specific occlusion diagnosis, check documentation.
Do not use for
Do not use this code for central retinal artery occlusion, branch retinal vein occlusion, or nonspecific visual symptoms alone. If the chart does not clearly identify a partial retinal artery occlusion, verify the diagnosis first.
Coding tip
Code only when the provider explicitly documents partial retinal artery occlusion; otherwise, query for a more specific retinal vascular diagnosis.