ICD-10 Code G43.40 – Hemiplegic migraine, not intractable (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G43.40 – Hemiplegic migraine, not intractable
What it is
G43.40 identifies hemiplegic migraine that is not documented as intractable. It describes a migraine disorder with temporary motor weakness on one side of the body, with the record not showing resistance to treatment.
Clinical signs
Typical documentation includes migraine headache plus reversible unilateral weakness, often with other aura features such as visual or sensory symptoms. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents hemiplegic migraine and does not state that it is intractable or refractory. It also fits when the note clearly describes migraine with transient hemiplegia and supports the diagnosis. If the record is unclear, check documentation before coding.
Do not use for
Do not use G43.40 if the provider documents intractable hemiplegic migraine, because that requires a different code. Do not assign it for stroke, transient ischemic attack, or nonspecific migraine without hemiplegic features.
Coding tip
Code only when hemiplegic migraine is explicitly documented; if laterality or intractability is missing, query the provider.