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ICD-10-CM 2027

ICD-10 code for Seizure disorder

G40.909

Epilepsy, unspecified, not intractable, without status epilepticus

✓ Billable / specific

From the official ICD-10-CM alphabetic index entry “Disorder (of) › seizure”. Page updated September 29, 2026.

About coding Seizure disorder

The ICD-10-CM code for Seizure disorder is G40.909 (Epilepsy, unspecified, not intractable, without status epilepticus). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G40.909.

Within G40.90, choose G40.909 (without status epilepticus) only when documentation doesn't support a more specific option: with status epilepticus (G40.901).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator, relative weight 5.7444), DRG 100 (Seizures with MCC, relative weight 1.9233) and DRG 101 (Seizures without MCC, relative weight 0.8952), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

More specific Seizure disorder codes (official index)

  • intractable G40.919 — Epilepsy, unspecified, intractable, without status epilepticus
  • with status epilepticus G40.911 — Epilepsy, unspecified, intractable, with status epilepticus

Common questions about Seizure disorder ICD-10 codes

What is the ICD-10 code for Seizure disorder?

G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus. More specific codes apply when the documentation supports them: G40.919, G40.911.

What is the ICD-10 code for intractable seizure disorder?

G40.919 — Epilepsy, unspecified, intractable, without status epilepticus.

Is G40.909 billable?

Yes. G40.909 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can G40.909 be used as a principal diagnosis?

Yes. The Medicare Code Editor doesn't restrict G40.909 as a principal diagnosis.

Is G40.909 a CC or MCC?

No. G40.909 is neither a CC nor an MCC under MS-DRG v44.0.