G40.84 ICD-10-CM Code: KCNQ2-related epilepsy
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
KCNQ2-related epilepsy is a non-billable ICD-10-CM category code (G40.84). A more specific billable subcode must be selected for claims submission.
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for G40.84 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)
Frequently Asked Questions (FAQ) & Clinical Guidance
Can G40.84 be billed directly?
No. G40.84 (KCNQ2-related epilepsy) 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 G40.84 in its code family, with their registry titles.
- G40.823 — Epileptic spasms, intractable, with status epilepticus
- G40.824 — Epileptic spasms, intractable, without status epilepticus
- G40.83 — Dravet syndrome
- G40.833 — Dravet syndrome, intractable, with status epilepticus
- G40.834 — Dravet syndrome, intractable, without status epilepticus
- G40.841 — KCNQ2-related epilepsy, not intractable, with status epilepticus
- G40.842 — KCNQ2-related epilepsy, not intractable, without status epilepticus
- G40.843 — KCNQ2-related epilepsy, intractable, with status epilepticus
- G40.844 — KCNQ2-related epilepsy, intractable, without status epilepticus
- G40.89 — Other seizures