ICD-10 Code E51.2 – Wernicke’s encephalopathy (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E51.2 – Wernicke’s encephalopathy
What it is
E51.2 identifies Wernicke’s encephalopathy, an acute neurologic condition caused by thiamine deficiency. It is a medical emergency and is often linked to malnutrition, alcohol use disorder, or other causes of poor vitamin B1 intake or absorption.
Clinical signs
Classic findings include confusion, gait instability, and eye movement abnormalities, but the full triad is not always present. Clinical features vary; refer to documentation.
When to use this code
Use E51.2 when the provider documents Wernicke’s encephalopathy, Wernicke disease, or acute thiamine-deficiency encephalopathy. It may also apply when the record clearly supports the diagnosis and the clinician treats it as such. Code the condition documented, not just risk factors such as alcoholism or malnutrition.
Do not use for
Do not use this code for uncomplicated thiamine deficiency without encephalopathy. If the record only notes confusion, ataxia, or alcohol-related problems without a confirmed diagnosis, check documentation.
Coding tip
Look for explicit provider wording of Wernicke’s encephalopathy and code any documented underlying nutritional deficiency separately when supported.