Skip to main content
ICD-10/G40.3

G40.3 ICD-10-CM Code: Generalized idiopathic epilepsy and epileptic syndromes

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Generalized idiopathic epilepsy and epileptic syndromes is a non-billable ICD-10-CM category code (G40.3). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for G40.3 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • conversion disorder with seizures (F44.5)
  • convulsions NOS (R56.9)
  • post traumatic seizures (R56.1)
  • seizure (convulsive) NOS (R56.9)
  • seizure of newborn (P90)

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • hippocampal sclerosis (G93.81)
  • mesial temporal sclerosis (G93.81)
  • temporal sclerosis (G93.81)
  • Todd's paralysis (G83.84)

Code Also

Additional codes that may be required to fully describe the encounter.

  • MERRF syndrome, if applicable (E88.42)

Frequently Asked Questions (FAQ) & Clinical Guidance

Can G40.3 be billed directly?

No. G40.3 (Generalized idiopathic epilepsy and epileptic syndromes) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to G40.3 in its code family, with their registry titles.

  • G40.201 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus
  • G40.209 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus
  • G40.21 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable
  • G40.211 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus
  • G40.219 — Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus
  • G40.30 — Generalized idiopathic epilepsy and epileptic syndromes, not intractable
  • G40.301 — Generalized idiopathic epilepsy and epileptic syndromes, not intractable, with status epilepticus
  • G40.309 — Generalized idiopathic epilepsy and epileptic syndromes, not intractable, without status epilepticus
  • G40.31 — Generalized idiopathic epilepsy and epileptic syndromes, intractable
  • G40.311 — Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus

View all codes in the G40 family