2026 ICD-10-CM Diagnosis Code G40.909Epilepsy, unspecified, not intractable, without status epilepticus
ICD-10-CM Codes›G00–G99›G40-G47›G40
- Billable — Valid for Submission
- Chronic Condition
G40.909 is a billable ICD-10-CM diagnosis code for epilepsy, unspecified, not intractable, without 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Epilepsy; convulsions.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormally short little finger
- Acute gastroenteritis
- Alopecia universalis
- Alopecia, epilepsy, intellectual disability syndrome Moynahan type
- Alopecia, psychomotor epilepsy, periodontal pyorrhea, intellectual disability syndrome
- Arachnoid cyst
- Atherosclerosis, deafness, diabetes, epilepsy, nephropathy syndrome
- Autism epilepsy syndrome due to branched chain ketoacid dehydrogenase kinase deficiency
- Autism spectrum disorder, epilepsy, arthrogryposis syndrome
- Autistic disorder of childhood onset
- Autosomal recessive cerebellar ataxia, epilepsy, intellectual disability syndrome due to RUBCN deficiency
- Autosomal recessive cerebellar ataxia, epilepsy, intellectual disability syndrome due to TUD deficiency
- Autosomal recessive cerebellar ataxia, epilepsy, intellectual disability syndrome due to WWOX deficiency
- Behavioral arrest epileptic seizure
- Benign infantile seizure with mild gastroenteritis syndrome
- Celiac disease
- Celiac disease with epilepsy and cerebral calcification syndrome
- CNTNAP2-related developmental and epileptic encephalopathy
- Congenital generalized hypertrichosis
- Congenital malformation of the meninges
- Congenital muscular dystrophy with intellectual disability and severe epilepsy
- Conjunctival telangiectasis
- Cortical blindness
- Dementia with behavioral disturbance
- Developmental and epileptic encephalopathy
- Developmental anomaly of periodontal tissue
- Disorder confirmed
- Disorder of glutamine metabolism
- Early infantile developmental and epileptic encephalopathy
- Early-onset epilepsy, intellectual disability, brain anomalies syndrome
- Early-onset epileptic encephalopathy, cortical blindness, intellectual disability, facial dysmorphism syndrome
- Epilepsy
- Epilepsy confirmed
- Epilepsy control good
- Epilepsy control poor
- Epilepsy co-occurrent and due to degenerative brain disorder
- Epilepsy co-occurrent and due to dementia
- Epilepsy co-occurrent and due to demyelinating disorder
- Epilepsy co-occurrent and due to mesial temporal sclerosis
- Epilepsy due to bacterial endocarditis
- Epilepsy due to cerebrovascular accident
- Epilepsy due to congenital anomaly of brain
- Epilepsy due to congenital infectious disease
- Epilepsy due to glucose transporter protein type 1 deficiency syndrome
- Epilepsy due to immune disorder
- Epilepsy due to infectious disease of central nervous system
- Epilepsy due to infectious encephalitis
- Epilepsy due to infectious meningitis
- Epilepsy due to intracranial neoplasm
- Epilepsy due to neonatal central nervous system infection
- Epilepsy due to parasitic disease
- Epilepsy due to perinatal anoxic-ischemic brain injury
- Epilepsy due to perinatal cerebral ischemia
- Epilepsy due to perinatal intraventricular hemorrhage
- Epilepsy due to perinatal periventricular hemorrhage
- Epilepsy in mother complicating childbirth
- Epilepsy in mother complicating pregnancy
- Epilepsy monitoring status
- Epilepsy telangiectasia syndrome
- Epilepsy treatment changed
- Epilepsy treatment started
- Epilepsy, microcephaly, skeletal dysplasia syndrome
- Epileptic dementia with behavioral disturbance
- Epileptic encephalopathy
- Epileptic encephalopathy with global cerebral demyelination
- Epileptic psychosis
- Epileptic seizure
- Epileptic seizure witnessed by history provider
- Epileptic seizures occurring only during sleep
- Epileptic vertigo
- Facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, gingival overgrowth syndrome
- GRIN2A developmental and epileptic encephalopathy
- Hyperekplexia epilepsy syndrome
- Hyperexplexia
- Impaired awareness epileptic seizure
- Impaired awareness nonmotor onset epileptic seizure
- Infant epilepsy with migrant focal crisis
- Infantile epileptic dyskinetic encephalopathy
- Infantile gastroenteritis
- Inherited disorder of folate metabolism
- Intellectual disability, epilepsy, bulbous nose syndrome
- Intellectual disability, epilepsy, extrapyramidal syndrome
- KCNQ2 developmental and epileptic encephalopathy
- Lanugo
- Macrogyria
- Maternal epilepsy due to perinatal stroke
- MEHMO syndrome
- Mesial temporal lobe sclerosis
- Microcephaly, intellectual disability, sensorineural hearing loss, epilepsy, abnormal muscle tone syndrome
- Motor epileptic seizure
- MTHFS-related developmental delay, microcephaly, short stature, epilepsy syndrome
- Multiple congenital anomalies, hypotonia, seizures syndrome
- Neonatal diabetes mellitus
- Neonatal epilepsy due to perinatal stroke
- Neonatal epileptic encephalopathy due to glutaminase deficiency
- Neurological disorder confirmed
- No epilepsy drug side effects
- No seizures on treatment
- Non-motor epileptic seizure
- Pachygyria, intellectual disability, epilepsy syndrome
- Paranoid-hallucinatory epileptic psychosis
- PCDH19 clustering epilepsy
- Periodontitis co-occurrent with genetic disorder
- Permanent neonatal diabetes mellitus
- Post-cerebrovascular accident epilepsy
- Postseizure confusion
- Postseizure delirium
- Posttraumatic seizure
- Primary microcephaly, epilepsy, permanent neonatal diabetes syndrome
- RNF13-related severe early-onset epileptic encephalopathy
- Scar epilepsy
- Self-limited familial neonatal-infantile epilepsy
- Severe intellectual disability, epilepsy, anal anomaly, distal phalangeal hypoplasia syndrome
- Skeletal dysplasia with epilepsy and short stature syndrome
- Spastic paraplegia, severe developmental delay, epilepsy syndrome
- STXBP1 developmental and epileptic encephalopathy
- SYNGAP1-related developmental and epileptic encephalopathy
- Temporal lobe sclerosis
- Third cranial nerve finding
- Transient epileptic amnesia
- Triple X syndrome, epilepsy, and hypogammaglobulinemia
- Vascular abnormality of conjunctiva
- X-linked epilepsy with learning disability and behavior disorder syndrome
- X-linked intellectual disability and epilepsy with progressive joint contracture and facial dysmorphism syndrome
- X-linked spasticity, intellectual disability, epilepsy syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Epilepsy NOS
- Epileptic convulsions NOS
- Epileptic fits NOS
- Epileptic seizures NOS
- Recurrent seizures NOS
- Seizure disorder NOS
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Disorder (of) - See Also: Disease;
- seizure - See Also: Epilepsy; - G40.909
- Epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure) - G40.909
- not intractable - G40.909
- without status epilepticus - G40.909
- Seizure (s) - See Also: Convulsions; - R56.9
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Disorder(of)
- seizure
- Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
- Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
- not intractable
- Epilepsy, epileptic, epilepsia(attack) (cerebral) (convulsion) (fit) (seizure)
- not intractable
- without status epilepticus
- Seizure(s)
- disorder
- Seizure(s)
- recurrent
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Celiac Disease
a malabsorption syndrome that is precipitated by the ingestion of foods containing gluten, such as wheat, rye, and barley. it is characterized by inflammation of the small intestine, loss of microvilli structure, failed intestinal absorption, and malnutrition.Drug Resistant Epilepsy
epileptic condition in which adequate trials of two tolerated and appropriately chosen and used antiepileptic drugs schedules to achieve sustained seizure freedom failed.Epilepsies, Myoclonic
a clinically diverse group of epilepsy syndromes characterized either by myoclonic seizures or by myoclonus in association with other seizure types. myoclonic epilepsy syndromes are divided into three subtypes based on etiology: familial, cryptogenic, and symptomatic.Epilepsies, Partial
conditions characterized by recurrent paroxysmal neuronal discharges which arise from a focal region of the brain. partial seizures are divided into simple and complex, depending on whether consciousness is unaltered (simple partial seizure) or disturbed (complex partial seizure). both types may feature a wide variety of motor, sensory, and autonomic symptoms. partial seizures may be classified by associated clinical features or anatomic location of the seizure focus. a secondary generalized seizure refers to a partial seizure that spreads to involve the brain diffusely. (from adams et al., principles of neurology, 6th ed, pp317)Epilepsy
a disorder characterized by recurrent episodes of paroxysmal brain dysfunction due to a sudden, disorderly, and excessive neuronal discharge. epilepsy classification systems are generally based upon: (1) clinical features of the seizure episodes (e.g., motor seizure), (2) etiology (e.g., post-traumatic), (3) anatomic site of seizure origin (e.g., frontal lobe seizure), (4) tendency to spread to other structures in the brain, and (5) temporal patterns (e.g., nocturnal epilepsy). (from adams et al., principles of neurology, 6th ed, p313)Epilepsy, Absence
a seizure disorder usually occurring in childhood characterized by rhythmic electrical brain discharges of generalized onset. clinical features include a sudden cessation of ongoing activity usually without loss of postural tone. rhythmic blinking of the eyelids or lip smacking frequently accompanies the seizures. the usual duration is 5-10 seconds, and multiple episodes may occur daily. juvenile absence epilepsy is characterized by the juvenile onset of absence seizures and an increased incidence of myoclonus and tonic-clonic seizures. (menkes, textbook of child neurology, 5th ed, p736)Epilepsy, Partial, Motor
a disorder characterized by recurrent localized paroxysmal discharges of cerebral neurons that give rise to seizures that have motor manifestations. the majority of partial motor seizures originate in the frontal lobe (see also epilepsy, frontal lobe). motor seizures may manifest as tonic or clonic movements involving the face, one limb or one side of the body. a variety of more complex patterns of movement, including abnormal posturing of extremities, may also occur.Epilepsy, Partial, Sensory
a disorder characterized by recurrent focal onset seizures which have sensory (i.e., olfactory, visual, tactile, gustatory, or auditory) manifestations. partial seizures that feature alterations of consciousness are referred to as complex partial seizures (epilepsy, complex partial).Epilepsy, Post-Traumatic
recurrent seizures causally related to craniocerebral trauma. seizure onset may be immediate but is typically delayed for several days after the injury and may not occur for up to two years. the majority of seizures have a focal onset that correlates clinically with the site of brain injury. cerebral cortex injuries caused by a penetrating foreign object (craniocerebral trauma, penetrating) are more likely than closed head injuries (head injuries, closed) to be associated with epilepsy. concussive convulsions are nonepileptic phenomena that occur immediately after head injury and are characterized by tonic and clonic movements. (from rev neurol 1998 feb;26(150):256-261; sports med 1998 feb;25(2):131-6)Epileptic Syndromes
epileptic seizures that are of similar type and age of onset and have other similar features (e.g., clinical course, eeg findings, genetic association and neuropathology).Lafora Disease
a form of stimulus sensitive myoclonic epilepsy inherited as an autosomal recessive condition. the most common presenting feature is a single seizure in the second decade of life. this is followed by progressive myoclonus, myoclonic seizures, tonic-clonic seizures, focal occipital seizures, intellectual decline, and severe motor and coordination impairments. most affected individuals do not live past the age of 25 years. concentric amyloid (lafora) bodies are found in neurons, liver, skin, bone, and muscle (from menkes, textbook of childhood neurology, 5th ed, pp111-110).Myoclonic Epilepsies, Progressive
a heterogeneous group of primarily familial epilepsy disorders characterized by myoclonic seizures, tonic-clonic seizures, ataxia, progressive intellectual deterioration, and neuronal degeneration. these include lafora disease; merrf syndrome; neuronal ceroid-lipofuscinosis; sialidosis (see mucolipidoses), and unverricht-lundborg syndrome.Myoclonic Epilepsy, Juvenile
a disorder characterized by the onset of myoclonus in adolescence, a marked increase in the incidence of absence seizures (see epilepsy, absence), and generalized major motor seizures (see epilepsy, tonic-clonic). the myoclonic episodes tend to occur shortly after awakening. seizures tend to be aggravated by sleep deprivation and alcohol consumption. hereditary and sporadic forms have been identified. (from adams et al., principles of neurology, 6th ed, p323)Unverricht-Lundborg Syndrome
an autosomal recessive condition characterized by recurrent myoclonic and generalized seizures, ataxia, slowly progressive intellectual deterioration, dysarthria, and intention tremor. myoclonic seizures are severe and continuous, and tend to be triggered by movement, stress, and sensory stimuli. the age of onset is between 8 and 13 years, and the condition is relatively frequent in the baltic region, especially finland. (from menkes, textbook of child neurology, 5th ed, pp109-110)Epilepsy, Tonic-Clonic
a generalized seizure disorder characterized by recurrent major motor seizures. the initial brief tonic phase is marked by trunk flexion followed by diffuse extension of the trunk and extremities. the clonic phase features rhythmic flexor contractions of the trunk and limbs, pupillary dilation, elevations of blood pressure and pulse, urinary incontinence, and tongue biting. this is followed by a profound state of depressed consciousness (post-ictal state) which gradually improves over minutes to hours. the disorder may be cryptogenic, familial, or symptomatic (caused by an identified disease process). (from adams et al., principles of neurology, 6th ed, p329)Epilepsy, Temporal Lobe
a localization-related (focal) form of epilepsy characterized by recurrent seizures that arise from foci within the temporal lobe, most commonly from its mesial aspect. a wide variety of psychic phenomena may be associated, including illusions, hallucinations, dyscognitive states, and affective experiences. the majority of complex partial seizures (see epilepsy, complex partial) originate from the temporal lobes. temporal lobe seizures may be classified by etiology as cryptogenic, familial, or symptomatic. (from adams et al., principles of neurology, 6th ed, p321).Epilepsy, Rolandic
an autosomal dominant inherited partial epilepsy syndrome with onset between age 3 and 13 years. seizures are characterized by paresthesia and tonic or clonic activity of the lower face associated with drooling and dysarthria. in most cases, affected children are neurologically and developmentally normal. (from epilepsia 1998 39;suppl 4:s32-s41)Epilepsy, Reflex
a subtype of epilepsy characterized by seizures that are consistently provoked by a certain specific stimulus. auditory, visual, and somatosensory stimuli as well as the acts of writing, reading, eating, and decision making are examples of events or activities that may induce seizure activity in affected individuals. (from neurol clin 1994 feb;12(1):57-8)Epilepsy, Generalized
recurrent conditions characterized by epileptic seizures which arise diffusely and simultaneously from both hemispheres of the brain. classification is generally based upon motor manifestations of the seizure (e.g., convulsive, nonconvulsive, akinetic, atonic, etc.) or etiology (e.g., idiopathic, cryptogenic, and symptomatic). (from mayo clin proc, 1996 apr;71(4):405-14)Epilepsy, Frontal Lobe
a localization-related (focal) form of epilepsy characterized by seizures which arise in the frontal lobe.Epilepsy, Complex Partial
a disorder characterized by recurrent partial seizures marked by impairment of cognition. during the seizure the individual may experience a wide variety of psychic phenomenon including formed hallucinations, illusions, deja vu, intense emotional feelings, confusion, and spatial disorientation. focal motor activity, sensory alterations and automatism may also occur. complex partial seizures often originate from foci in one or both temporal lobes. the etiology may be idiopathic (cryptogenic partial complex epilepsy) or occur as a secondary manifestation of a focal cortical lesion (symptomatic partial complex epilepsy). (from adams et al., principles of neurology, 6th ed, pp317-8)Epilepsy, Benign Neonatal
a condition marked by recurrent seizures that occur during the first 4-6 weeks of life despite an otherwise benign neonatal course. autosomal dominant familial and sporadic forms have been identified. seizures generally consist of brief episodes of tonic posturing and other movements, apnea, eye deviations, and blood pressure fluctuations. these tend to remit after the 6th week of life. the risk of developing epilepsy at an older age is moderately increased in the familial form of this disorder. (neurologia 1996 feb;11(2):51-5)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)Seizures
clinical or subclinical disturbances of cortical function due to a sudden, abnormal, excessive, and disorganized discharge of brain cells. clinical manifestations include abnormal motor, sensory and psychic phenomena. recurrent seizures are usually referred to as epilepsy or seizure disorder.Automatism
automatic, mechanical, and apparently undirected behavior which is outside of conscious control.Frontal Lobe
the part of the cerebral hemisphere anterior to the central sulcus, and anterior and superior to the lateral sulcus.Permanent Neonatal Diabetes Mellitus
hyperglycemia in the first month of life due to a genetically determined defect in the structure, secretion and/or function of insulin that does not resolve spontaneously.Cortical Blindness
visual impairment due to visual cortex dysfunction.Lanugo
fine downy hair that covers the body of a human fetus beginning in the fifth month of gestation; it is usually shed by the ninth month of gestation.
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
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Convert G40.909 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G40.909Overview
Is G40.909 (Epilepsy, unspecified, not intractable) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report epilepsy, unspecified, not intractable, without status epilepticus on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does G40.909 group to?
When epilepsy, unspecified, not intractable, without 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 G40.909?
Under the General Equivalence Mappings, epilepsy, unspecified, not intractable, without 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.
