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G40.81 ICD-10-CM Code: Lennox-Gastaut syndrome

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

Official Registry Overview & Definition

Lennox-Gastaut syndrome is a non-billable ICD-10-CM category code (G40.81). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for G40.81 in the official ICD-10-CM tabular list.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Excludes2 — Not Included Here

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

Frequently Compared Codes

The official Excludes notes on G40.81 name these codes. Each comparison page covers when the two can — or must not — be reported together.

Change history

No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Relationships & Classification

Official ICD-10-CM tabular notes on other codes that name G40.81 or its code family.

3 Excludes1 notes across 2 chapters: G25.3 (via G40.-), R56 (via G40.-), R56.1 (via G40.-).

2 Excludes2 notes: F44.0 (via G40.-), F44.1 (via G40.-).

1 Code First instructions: F02 (via G40.-).

2 Use Additional Code instructions: Q87.87 (via G40.-), Q93.52 (via G40.-).

9 Code Also instructions across 7 chapters: E20.810 (via G40.-), F78.A1 (via G40.-), G04.8 (via G40.-), G43.1 (via G40.-), G93.45 (via G40.-), I67.850 (via G40.-), Q87.85 (via G40.-), QA0 (via G40.-), Z15.1 (via G40.-).

Contextual Map

Every relationship of G40.81 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • G00-G99 — Chapter 6: Diseases of the Nervous System (G00-G99) (G00-G99) [Hierarchy]

Referenced by Excludes1 notes

  • G25.3 — Myoclonus [Excludes1](via G40.-): “myoclonic epilepsy (G40.-)” · check together
  • R56 — Convulsions, not elsewhere classified [Excludes1](via G40.-): “epileptic convulsions and seizures (G40.-)” · check together
  • R56.1 — Post traumatic seizures [Excludes1](via G40.-): “post traumatic epilepsy (G40.-)” · check together

Referenced by Excludes2 notes

  • F44.0 — Dissociative amnesia [Excludes2](via G40.-): “postictal amnesia in epilepsy (G40.-)” · check together
  • F44.1 — Dissociative fugue [Excludes2](via G40.-): “postictal fugue in epilepsy (G40.-)” · check together

Referenced by Code First instructions

  • F02 — Dementia in other diseases classified elsewhere [Code First](via G40.-): “epilepsy and recurrent seizures (G40.-)” · check together

Referenced by Use Additional Code instructions

  • Q87.87 — Hao-Fountain Syndrome [Use Additional Code](via G40.-): “epilepsy, by specific type (G40.-)” · check together
  • Q93.52 — Phelan-McDermid syndrome [Use Additional Code](via G40.-): “epilepsy and recurrent seizures (G40.-)” · check together

Referenced by Code Also instructions (9)

  • E20.810 — Autosomal dominant hypocalcemia [Code Also](via G40.-): “seizure disorder (G40.-, R56.9)” · check together
  • F78.A1 — SYNGAP1-related intellectual disability [Code Also](via G40.-): “epilepsy and recurrent seizures (G40.-)” · check together
  • G04.8 — Other encephalitis, myelitis and encephalomyelitis [Code Also](via G40.-): “any associated seizure (G40.-, R56.9)” · check together
  • G43.1 — Migraine with aura [Code Also](via G40.-): “any associated seizure (G40.-, R56.9)” · check together
  • G93.45 — Developmental and epileptic encephalopathy [Code Also](via G40.-): “epilepsy, by specific type (G40.-)” · check together
  • I67.850 — Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [Code Also](via G40.-): “epilepsy (G40.-)” · check together
  • Q87.85 — MED13L syndrome [Code Also](via G40.-): “epilepsy and recurrent seizures (G40.-)” · check together
  • QA0 — Neurodevelopmental disorders related to specific genetic pathogenic variants [Code Also](via G40.-): “epilepsy, by specific type (G40.-)” · check together
  • and 1 more

Nearest codes (40)

  • G40 — Epilepsy and recurrent seizures [Sibling]
  • G40.311 — Generalized idiopathic epilepsy and epileptic syndromes, intractable, with status epilepticus [Sibling]
  • G40.319 — Generalized idiopathic epilepsy and epileptic syndromes, intractable, without status epilepticus [Sibling]
  • G40.4 — Other generalized epilepsy and epileptic syndromes [Sibling]
  • G40.40 — Other generalized epilepsy and epileptic syndromes, not intractable [Sibling]
  • G40.401 — Other generalized epilepsy and epileptic syndromes, not intractable, with status epilepticus [Sibling]
  • G40.409 — Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus [Sibling]
  • G40.41 — Other generalized epilepsy and epileptic syndromes, intractable [Sibling]
  • and 32 more

Frequently Asked Questions (FAQ) & Clinical Guidance

Can G40.81 be billed directly?

No. G40.81 (Lennox-Gastaut syndrome) 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 G40.81 in its code family, with their registry titles.

  • G40.80 — Other epilepsy
  • G40.801 — Other epilepsy, not intractable, with status epilepticus
  • G40.802 — Other epilepsy, not intractable, without status epilepticus
  • G40.803 — Other epilepsy, intractable, with status epilepticus
  • G40.804 — Other epilepsy, intractable, without status epilepticus
  • G40.811 — Lennox-Gastaut syndrome, not intractable, with status epilepticus
  • G40.812 — Lennox-Gastaut syndrome, not intractable, without status epilepticus
  • G40.813 — Lennox-Gastaut syndrome, intractable, with status epilepticus
  • G40.814 — Lennox-Gastaut syndrome, intractable, without status epilepticus
  • G40.82 — Epileptic spasms

View all codes in the G40 family