ICD-10 Code G40.009 – Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G40.009 – Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus
What it is
This code identifies idiopathic focal epilepsy with seizures that begin in one area of the brain. It is used when the epilepsy is not intractable and there is no status epilepticus.
Clinical signs
Typical findings include recurrent focal seizures with localized onset, with or without awareness impairment. Clinical features vary; refer to documentation for seizure type, frequency, and any EEG or neurologic findings.
When to use this code
Use G40.009 when the clinician documents idiopathic focal epilepsy or a focal epileptic syndrome with localized-onset seizures and does not describe it as intractable. Apply it when status epilepticus is not present.
If the record only says “focal seizures” without confirming epilepsy, check documentation. Make sure the note supports an idiopathic epilepsy diagnosis rather than a symptomatic or unspecified seizure disorder.
Do not use for
Do not use this code for intractable epilepsy, status epilepticus, or seizures not documented as localized onset. Check documentation if the record instead describes generalized seizures or another epilepsy type.
Coding tip
Verify that both “not intractable” and “without status epilepticus” are documented before assigning G40.009.