2026 ICD-10-CM Diagnosis Code G40.901Epilepsy, unspecified, not intractable, with status epilepticus

ICD-10-CM Codes›G00–G99›G40-G47›G40

ICD-10-CM G40.901
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G40.901 is a billable ICD-10-CM diagnosis code for epilepsy, unspecified, not intractable, with status epilepticus. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 100 through 101. Coders also document this condition as idiopathic partial status epilepticus. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions.

Code Identity

ICD-10-CM Code
G40.901
Billable Status
Yes — Valid for Submission
Code Describes
Epilepsy, unspecified, not intractable, with status epilepticus
Short Description
Epilepsy, unsp, not intractable, with status epilepticus
Parent Code
G40.90
Epilepsy, unspecified, not intractable

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG40Epilepsy and recurrent seizures
This CodeG40.901Epilepsy, unspecified, not intractable, with status epilepticus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Idiopathic partial status epilepticus
  • Status epilepticus
  • Status epilepticus with prominent motor symptoms

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Convulsions(idiopathic)
      • febrile
        • with status epilepticus
    • Convulsions(idiopathic)
      • febrile
        • complex
          • with status epilepticus
    • Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
      • not intractable
        • with status epilepticus
    • Seizure(s)
      • febrile (simple)
        • with status epilepticus
    • Seizure(s)
      • febrile (simple)
        • complex (atypical) (complicated)
          • with status epilepticus
    • Status(post)
      • epileptic, epilepticus

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS009
Epilepsy; convulsions
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Alcohol Withdrawal Seizures

    a condition where seizures occur in association with ethanol abuse (alcoholism) without other identifiable causes. seizures usually occur within the first 6-48 hours after the cessation of alcohol intake, but may occur during periods of alcohol intoxication. single generalized tonic-clonic motor seizures are the most common subtype, however, status epilepticus may occur. (adams et al., principles of neurology, 6th ed, p1174)

  • Status Epilepticus

    a prolonged seizure or seizures repeated frequently enough to prevent recovery between episodes occurring over a period of 20-30 minutes. the most common subtype is generalized tonic-clonic status epilepticus, a potentially fatal condition associated with neuronal injury and respiratory and metabolic dysfunction. nonconvulsive forms include petit mal status and complex partial status, which may manifest as behavioral disturbances. simple partial status epilepticus consists of persistent motor, sensory, or autonomic seizures that do not impair cognition (see also epilepsia partialis continua). subclinical status epilepticus generally refers to seizures occurring in an unresponsive or comatose individual in the absence of overt signs of seizure activity. (from n engl j med 1998 apr 2;338(14):970-6; neurologia 1997 dec;12 suppl 6:25-30)

  • Epilepsia Partialis Continua

    a variant of epilepsy characterized by continuous focal jerking of a body part over a period of hours, days, or even years without spreading to other body regions. contractions may be aggravated by movement and are reduced, but not abolished during sleep. electroencephalography demonstrates epileptiform (spike and wave) discharges over the hemisphere opposite to the affected limb in most instances. the repetitive movements may originate from the cerebral cortex or from subcortical structures (e.g., brain stem; basal ganglia). this condition is associated with russian spring and summer encephalitis (see encephalitis, tick borne); rasmussen syndrome (see encephalitis); multiple sclerosis; diabetes mellitus; brain neoplasms; and cerebrovascular disorders. (from brain, 1996 april;119(pt2):393-407; epilepsia 1993;34;suppl 1:s29-s36; and adams et al., principles of neurology, 6th ed, p319)

  • Simple Partial Motor Status Epilepticus|Motor simple partial status|SPMSE

    status epilepticus that is characterized by focal motor seizures of which the individual is aware.

  • Simple Partial Status Epilepticus|SPSE

    status epilepticus that is characterized by focal seizures of which the individual is aware.

  • Juvenile Myoclonic Epilepsy, Intractable, with Status Epilepticus|Juvenile myoclonic epilepsy, intractable, with status epilepticus

    evidence of juvenile myoclonic epilepsy, with status epilepticus that does not respond optimally to treatment.

  • Generalized Idiopathic Epilepsy, not Intractable, without Status Epilepticus|Generalized idiopathic epilepsy, not intractable, without status epilepticus

    evidence of generalized idiopathic epilepsy without status epilepticus that responds to treatment.

  • Generalized Idiopathic Epilepsy, not Intractable, with Status Epilepticus|Generalized idiopathic epilepsy, not intractable, with status epilepticus

    evidence of generalized idiopathic epilepsy with status epilepticus that responds to treatment.

  • Generalized Idiopathic Epilepsy, Intractable, without Status Epilepticus|Generalized idiopathic epilepsy, intractable, without status epilepticus

    evidence of generalized idiopathic epilepsy, without status epilepticus that does not respond optimally to treatment.

  • Generalized Idiopathic Epilepsy, Intractable, with Status Epilepticus|Generalized idiopathic epilepsy, intractable, with status epilepticus

    evidence of generalized idiopathic epilepsy, with status epilepticus that does not respond optimally to treatment.

  • Epileptic Spasms, not Intractable, without Status Epilepticus|Epileptic spasms, not intractable, without status epilepticus

    evidence of epileptic spasms without status epilepticus that responds to treatment.

  • Epileptic Spasms, not Intractable, with Status Epilepticus|Epileptic spasms, not intractable, with status epilepticus

    evidence of epileptic spasms with status epilepticus that responds to treatment.

  • Epileptic Spasms, Intractable, without Status Epilepticus|Epileptic spasms, intractable, without status epilepticus

    evidence of epileptic spasms, without status epilepticus that does not respond optimally to treatment.

  • Epileptic Spasms, Intractable, with Status Epilepticus|Epileptic spasms, intractable, with status epilepticus

    evidence of epileptic spasms, with status epilepticus that does not respond optimally to treatment.

  • Epileptic Seizure Related To External Causes, not Intractable, without Status Epilepticus|Epileptic seizure related to external causes, not intractable, without status epilepticus

    evidence of epileptic seizure related to external causes without status epilepticus that responds to treatment.

  • Epileptic Seizure Related To External Causes, not Intractable, with Status Epilepticus|Epileptic seizure related to external causes, not intractable, with status epilepticus

    evidence of epileptic seizure related to external causes with status epilepticus that responds to treatment.

  • Localization-Related Idiopathic Epilepsy and Epileptic Syndromes with Seizures of Localized Onset, not Intractable, with Status Epilepticus|Localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, with status epilepticus

    evidence of localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset with status epilepticus that responds to treatment.

  • Localization-Related Idiopathic Epilepsy and Epileptic Syndromes with Seizures of Localized Onset, Intractable, without Status Epilepticus|Localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, without status epilepticus

    evidence of localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, without status epilepticus that does not respond optimally to treatment.

  • Localization-Related Idiopathic Epilepsy and Epileptic Syndromes with Seizures of Localized Onset, Intractable, with Status Epilepticus|Localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus

    evidence of localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, with status epilepticus that does not respond optimally to treatment.

  • Lennox-Gastaut Syndrome, not Intractable, without Status Epilepticus|Lennox-Gastaut syndrome, not intractable, without status epilepticus

    evidence of lennox-gastaut syndrome without status epilepticus that responds to treatment.

  • Lennox-Gastaut Syndrome, not Intractable, with Status Epilepticus|Lennox-Gastaut syndrome, not intractable, with status epilepticus

    evidence of lennox-gastaut syndrome with status epilepticus that responds to treatment.

  • Lennox-Gastaut Syndrome, Intractable, without Status Epilepticus|Lennox-Gastaut syndrome, intractable, without status epilepticus

    evidence of lennox-gastaut syndrome, without status epilepticus that does not respond optimally to treatment.

  • Lennox-Gastaut Syndrome, Intractable, with Status Epilepticus|Lennox-Gastaut syndrome, intractable, with status epilepticus

    evidence of lennox-gastaut syndrome, with status epilepticus that does not respond optimally to treatment.

  • Juvenile Myoclonic Epilepsy, not Intractable, without Status Epilepticus|Juvenile myoclonic epilepsy, not intractable, without status epilepticus

    evidence of juvenile myoclonic epilepsy without status epilepticus that responds to treatment.

  • Juvenile Myoclonic Epilepsy, not Intractable, with Status Epilepticus|Juvenile myoclonic epilepsy, not intractable, with status epilepticus

    evidence of juvenile myoclonic epilepsy with status epilepticus that responds to treatment.

  • Juvenile Myoclonic Epilepsy, Intractable, without Status Epilepticus|Juvenile myoclonic epilepsy, intractable, without status epilepticus

    intractable juvenile myoclonic epilepsy which is not associated with an acute, prolonged epileptic crisis.

  • Other Generalized Epilepsy, not Intractable, with Status Epilepticus|Other generalized epilepsy, not intractable, with stat epi

    evidence of other generalized epilepsy with status epilepticus that has some acceptable treatment options not specified elsewhere.

  • Other Generalized Epilepsy, Intractable, without Status Epilepticus|Other generalized epilepsy, intractable, without stat epi

    evidence of other generalized epilepsy, without status epilepticus that does not respond optimally to treatment not specified elsewhere.

  • Other Generalized Epilepsy, Intractable, with Status Epilepticus|Other generalized epilepsy, intractable, with status epilepticus

    evidence of other generalized epilepsy, with status epilepticus that does not respond optimally to treatment not specified elsewhere.

  • Other Epilepsy, not Intractable, without Status Epilepticus|Other epilepsy, not intractable, without status epilepticus

    evidence of other epilepsy without status epilepticus that has some acceptable treatment options not specified elsewhere.

  • Other Epilepsy, not Intractable, with Status Epilepticus|Other epilepsy, not intractable, with status epilepticus

    evidence of other epilepsy with status epilepticus that has some acceptable treatment options not specified elsewhere.

  • Other Epilepsy, Intractable, without Status Epilepticus|Other epilepsy, intractable, without status epilepticus

    evidence of other epilepsy, without status epilepticus that does not respond optimally to treatment not specified elsewhere.

  • Other Epilepsy, Intractable, with Status Epilepticus|Other epilepsy, intractable, with status epilepticus

    evidence of other epilepsy, with status epilepticus that does not respond optimally to treatment not specified elsewhere.

  • Non-Convulsive Status Epilepticus

    status epilepticus without prominent motor symptoms, the duration of which is at least ten minutes.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Simple Partial Seizures, not Intractable, without Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, without status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures without status epilepticus that responds to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Simple Partial Seizures, not Intractable, with Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures with status epilepticus that responds to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Simple Partial Seizures, Intractable, without Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, without status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, without status epilepticus that does not respond optimally to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Simple Partial Seizures, Intractable, with Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, intractable, with status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with simple partial seizures, with status epilepticus that does not respond optimally to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Complex Partial Seizures, not Intractable, without Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, without status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures without status epilepticus that responds to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Complex Partial Seizures, not Intractable, with Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, not intractable, with status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures with status epilepticus that responds to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Complex Partial Seizures, Intractable, without Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, without status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, without status epilepticus that does not respond optimally to treatment.

  • Localization-Related Symptomatic Epilepsy and Epileptic Syndromes with Complex Partial Seizures, Intractable, with Status Epilepticus|Localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable, with status epilepticus

    evidence of localization-related symptomatic epilepsy and epileptic syndromes with complex partial seizures, with status epilepticus that does not respond optimally to treatment.

  • Localization-Related Idiopathic Epilepsy and Epileptic Syndromes with Seizures of Localized Onset, not Intractable, without Status Epilepticus|Localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset, not intractable, without status epilepticus

    evidence of localization-related idiopathic epilepsy and epileptic syndromes with seizures of localized onset without status epilepticus that responds to treatment.

  • Absence Epileptic Syndrome, Intractable, with Status Epilepticus|Absence epileptic syndrome, intractable, with status epilepticus

    evidence of absence epileptic syndrome with status epilepticus that does not respond optimally to treatment.

  • Absence Epileptic Syndrome, Intractable, without Status Epilepticus|Absence epileptic syndrome, intractable, without status epilepticus

    evidence of absence epileptic syndrome without status epilepticus that does not respond optimally to treatment.

  • Absence Epileptic Syndrome, not Intractable, with Status Epilepticus|Absence epileptic syndrome, not intractable, with status epilepticus

    evidence of absence epileptic syndrome with status epilepticus that responds to treatment.

  • Absence Epileptic Syndrome, not Intractable, without Status Epilepticus|Absence epileptic syndrome, not intractable, without status epilepticus

    evidence of absence epileptic syndrome without status epilepticus that responds to treatment.

  • Dravet Syndrome, Intractable, with Status Epilepticus|Dravet syndrome, intractable, with status epilepticus

    evidence of dravet syndrome, with status epilepticus that does not respond optimally to treatment.

  • Dravet Syndrome, Intractable, without Status Epilepticus|Dravet syndrome, intractable, without status epilepticus

    evidence of dravet syndrome, without status epilepticus that does not respond optimally to treatment.

  • Epilepsy, Unspecified, Intractable, with Status Epilepticus|Epilepsy, unspecified, intractable, with status epilepticus

    evidence of unspecified epilepsy with status epilepticus that does not respond optimally to treatment.

  • Epilepsy, Unspecified, Intractable, without Status Epilepticus|Epilepsy, unspecified, intractable, without status epilepticus

    evidence of unspecified epilepsy without status epilepticus that does not respond optimally to treatment.

  • Epilepsy, Unspecified, not Intractable, with Status Epilepticus|Epilepsy, unspecified, not intractable, with status epilepticus

    evidence of unspecified epilepsy with status epilepticus that responds to treatment.

  • Epilepsy, Unspecified, not Intractable, without Status Epilepticus|Epilepsy, unspecified, not intractable, without status epilepticus

    evidence of unspecified epilepsy without status epilepticus that responds to treatment.

  • Other Generalized Epilepsy, not Intractable, without Status Epilepticus|Other generalized epilepsy, not intractable, without stat epi

    evidence of other generalized epilepsy without status epilepticus that has some acceptable treatment options not specified elsewhere.

  • Status Epilepticus

    a life-threatening situation in which the brain is in a continuous state of seizure.

Patient EducationClinical

Epilepsy

Epilepsy is a brain disorder that causes people to have recurring seizures. The seizures happen when clusters of nerve cells, or neurons, in the brain send out the wrong signals. People may have strange sensations and emotions or behave strangely. They may have violent muscle spasms or lose consciousness.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G40.901 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
345.90 Epilep NOS w/o intr epil
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G40.901Overview

Is G40.901 (Epilepsy, unspecified, not intractable) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report epilepsy, unspecified, not intractable, with status epilepticus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does G40.901 group to?

When epilepsy, unspecified, not intractable, with status epilepticus is the principal diagnosis on an inpatient stay, it groups to MS-DRG 100, 101, with relative weights from 0.9026 to 1.9368 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of G40.901?

Under the General Equivalence Mappings, epilepsy, unspecified, not intractable, with status epilepticus converts to ICD-9-CM 345.90 (epilep NOS w/o intr epil). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.