ICD-10 Code G40.841 – KCNQ2-related epilepsy, not intractable, with status epilepticus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G40.841 – KCNQ2-related epilepsy, not intractable, with status epilepticus
What it is
This code identifies epilepsy caused by a KCNQ2 gene disorder when the seizures are not described as intractable and the patient is currently in status epilepticus. Use it for documented KCNQ2-related epilepsy with prolonged or continuous seizure activity.
Clinical signs
Clinical features vary; refer to documentation. Status epilepticus means seizures are ongoing or recur without full recovery between events, and the record should also support a KCNQ2-related epilepsy diagnosis.
When to use this code
Use this code when the provider documents KCNQ2-related epilepsy and specifically states status epilepticus, while also indicating the epilepsy is not intractable. It is appropriate for inpatient, emergency, or specialist notes that clearly connect the genetic epilepsy diagnosis to the active seizure emergency.
Do not infer status epilepticus from a brief seizure history alone. If the chart says “refractory,” “intractable,” or does not specify seizure status, check documentation before coding.
Do not use for
Do not use this code for KCNQ2-related epilepsy without status epilepticus, or when the record documents intractable epilepsy instead. Check documentation if the seizure type or severity is unclear.
Coding tip
Always confirm both elements: the KCNQ2-related epilepsy diagnosis and the nonintractable status epilepticus wording.