ICD-10-CM 2027
ICD-10 code for disorder seizure
From the official ICD-10-CM alphabetic index entry “Seizure (s) › disorder”. Page updated September 29, 2026.
About coding disorder seizure
The ICD-10-CM code for disorder seizure is G40.909 (Epilepsy, unspecified, not intractable, without status epilepticus).
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.
Common questions about disorder seizure ICD-10 codes
What is the ICD-10 code for disorder seizure?
- G40.909 — Epilepsy, unspecified, not 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.