2026 ICD-10-CM Diagnosis Code G40.101Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus

ICD-10-CM Codes›G00–G99›G40-G47›G40

ICD-10-CM G40.101
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G40.101 is a billable ICD-10-CM diagnosis code for localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, 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 clonic epileptic seizure. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions.

Code Identity

ICD-10-CM Code
G40.101
Billable Status
Yes — Valid for Submission
Code Describes
Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus
Short Description
Local-rel symptc epi w simp part seiz, not ntrct, w stat epi
Parent Code
G40.10
Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG40-G47Episodic and paroxysmal disorders
CategoryG40Epilepsy and recurrent seizures
This CodeG40.101Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Clonic epileptic seizure
  • Epilepsia partialis continua
  • Focal onset clonic epileptic seizure
  • 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.

    • Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
      • localization-related (focal) (partial)
        • symptomatic
          • with simple partial seizures
            • not intractable
              • with status epilepticus
    • Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
      • syndromes
        • localization-related (focal) (partial)
          • symptomatic
            • with simple partial seizures
              • not intractable
                • with status epilepticus
    • Kozhevnikof's epilepsy
      • not intractable
        • with status 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

  • 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)

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 G40.101 to ICD-9-CMHistory

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

ICD-9-CM
345.50 Part epil w/o intr epil
Approximate The match is approximate rather than exact.
ICD-9-CM
345.70 Epil par cont w/o int ep
Approximate The match is approximate rather than exact.
ICD-9-CM
345.80 Epilep NEC 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 G40.101Overview

Is G40.101 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does G40.101 group to?

When localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, 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 G40.101?

Under the General Equivalence Mappings, localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures, not intractable, with status epilepticus converts to ICD-9-CM 345.50 (part epil w/o intr epil), 345.70 (epil par cont w/o int ep), and 345.80 (epilep NEC 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.