ICD-10 Code G40.814 – Lennox-Gastaut syndrome, intractable, without status epilepticus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G40.814 – Lennox-Gastaut syndrome, intractable, without status epilepticus
What it is
G40.814 identifies Lennox-Gastaut syndrome when seizures remain difficult to control and the patient is not in status epilepticus. Use it for this specific epileptic syndrome, not for generalized seizure disorders broadly.
Clinical signs
Typical findings include multiple seizure types, developmental impairment, and an abnormal EEG pattern consistent with Lennox-Gastaut syndrome. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record clearly states Lennox-Gastaut syndrome and documents that it is intractable or refractory. The documentation should also indicate there is no status epilepticus at the time of coding. If the note only says epilepsy or seizures, check documentation.
Do not use for
Do not use it for Lennox-Gastaut syndrome without intractability, or when status epilepticus is present. Also avoid it if the diagnosis is uncertain or not explicitly documented.
Coding tip
Confirm both “intractable” and “without status epilepticus” in the provider’s wording before assigning G40.814.