ICD-10 Code for Epilepsy

The default ICD-10-CM 2027 code for epilepsy, epileptic, epilepsia (attack) (cerebral) (convulsion) (fit) (seizure) is G40.909 – Epilepsy, unspecified, not intractable, without status epilepticus. More specific codes depend on the details documented, as listed in the official index (59 codes, 56 billable).

Main code: G40.909 – Epilepsy, unspecified, not intractable, without status epilepticus
Billable: Yes

Index entries for Epilepsy

Note: the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically)
with
- complex partial seizures – see Epilepsy, localization-related, symptomatic, with complex partial seizures
- grand mal seizures on awakening – see Epilepsy, generalized, specified NEC
- myoclonic absences – see Epilepsy, generalized, specified NEC
- myoclonic-astatic seizures – see Epilepsy, generalized, specified NEC
- simple partial seizures – see Epilepsy, localization-related, symptomatic, with simple partial seizures
akinetic – see Epilepsy, generalized, specified NEC
benign childhood with centrotemporal EEG spikes – see Epilepsy, localization-related, idiopathic
benign myoclonic in infancy – G40.80- (header)
Bravais-jacksonian – see Epilepsy, localization-related, symptomatic, with simple partial seizures
childhood
- with occipital EEG paroxysms – see Epilepsy, localization-related, idiopathic
- absence – G40.A09
  - intractable – G40.A19
    - with status epilepticus – G40.A11
    - without status epilepticus – G40.A19
  - not intractable – G40.A09
    - with status epilepticus – G40.A01
    - without status epilepticus – G40.A09
climacteric – see Epilepsy, specified NEC
cysticercosis – B69.0
deterioration (mental) – F06.8
due to syphilis – A52.19
focal – see Epilepsy, localization-related, symptomatic, with simple partial seizures
generalized
- idiopathic – G40.309
  - intractable – G40.319
    - with status epilepticus – G40.311
    - without status epilepticus – G40.319
  - not intractable – G40.309
    - with status epilepticus – G40.301
    - without status epilepticus – G40.309
- specified NEC – G40.409
  - intractable – G40.419
    - with status epilepticus – G40.411
    - without status epilepticus – G40.419
  - not intractable – G40.409
    - with status epilepticus – G40.401
    - without status epilepticus – G40.409
impulsive petit mal – see Epilepsy, juvenile myoclonic
intractable – G40.919
- with status epilepticus – G40.911
- without status epilepticus – G40.919
juvenile absence – G40.A09
- intractable – G40.A19
  - with status epilepticus – G40.A11
  - without status epilepticus – G40.A19
- not intractable – G40.A09
  - with status epilepticus – G40.A01
  - without status epilepticus – G40.A09
juvenile myoclonic – G40.B09
- intractable – G40.B19
  - with status epilepticus – G40.B11
  - without status epilepticus – G40.B19
- not intractable – G40.B09
  - with status epilepticus – G40.B01
  - without status epilepticus – G40.B09
KCNQ2-related – G40.842
- intractable – G40.844
  - with status epilepticus – G40.843
  - without status epilepticus – G40.844
- not intractable – G40.842
  - with status epilepticus – G40.841
  - without status epilepticus – G40.842
Lafora progressive myoclonus – G40.C09 – see also Epilepsy, myoclonus, progressive, Lafora
localization-related (focal) (partial)
- idiopathic – G40.009
  - with seizures of localized onset – G40.009
    - intractable – G40.019
      - with status epilepticus – G40.011
      - without status epilepticus – G40.019
    - not intractable – G40.009
      - with status epilepticus – G40.001
      - without status epilepticus – G40.009
- symptomatic
  - with complex partial seizures – G40.209
    - intractable – G40.219
      - with status epilepticus – G40.211
      - without status epilepticus – G40.219
    - not intractable – G40.209
      - with status epilepticus – G40.201
      - without status epilepticus – G40.209
  - with simple partial seizures – G40.109
    - intractable – G40.119
      - with status epilepticus – G40.111
      - without status epilepticus – G40.119
    - not intractable – G40.109
      - with status epilepticus – G40.101
      - without status epilepticus – G40.109
myoclonus, myoclonic – see also Epilepsy, generalized, specified NEC
- progressive – see also Epilepsy, generalized, idiopathic
  - Lafora – G40.C09
    - intractable – G40.C19
      - with status epilepticus – G40.C11
      - without status epilepticus – G40.C19
    - not intractable – G40.C09
      - with status epilepticus – G40.C01
      - without status epilepticus – G40.C09
  - type 1 – see Epilepsy, generalized, idiopathic
  - type 2 – see Epilepsy, myoclonus, progressive, Lafora
- severe, in infancy (SMEI) – G40.83- (header)
not intractable – G40.909
- with status epilepticus – G40.901
- without status epilepticus – G40.909
on awakening – see Epilepsy, generalized, specified NEC
parasitic NOS – B71.9 – G94 [manifestation]
partial – see Epilepsy, localization-related, symptomatic, with simple partial seizures
partialis continua – G40.1- (header) – see also Kozhevnikof's epilepsy
peripheral – see Epilepsy, specified NEC
polymorphic, in infancy (PMEI) – G40.83- (header)
procursiva – see Epilepsy, localization-related, symptomatic, with simple partial seizures
progressive (familial) – see Epilepsy, myoclonus, progressive
- Lafora – G40.C09 – see also Epilepsy, myoclonus, progressive, Lafora
reflex – see Epilepsy, specified NEC
related to
- alcohol – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
- drugs – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
- external causes – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
- hormonal changes – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
- sleep deprivation – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
- stress – G40.509
  - not intractable – G40.509
    - with status epilepticus – G40.501
    - without status epilepticus – G40.509
somatomotor – see Epilepsy, localization-related, symptomatic, with simple partial seizures
somatosensory – see Epilepsy, localization-related, symptomatic, with simple partial seizures
spasms – G40.822
- intractable – G40.824
  - with status epilepticus – G40.823
  - without status epilepticus – G40.824
- not intractable – G40.822
  - with status epilepticus – G40.821
  - without status epilepticus – G40.822
specified NEC – G40.802
- intractable – G40.804
  - with status epilepticus – G40.803
  - without status epilepticus – G40.804
- not intractable – G40.802
  - with status epilepticus – G40.801
  - without status epilepticus – G40.802
syndromes
- generalized
  - idiopathic – G40.309
    - intractable – G40.319
      - with status epilepticus – G40.311
      - without status epilepticus – G40.319
    - not intractable – G40.309
      - with status epilepticus – G40.301
      - without status epilepticus – G40.309
  - specified NEC – G40.409
    - intractable – G40.419
      - with status epilepticus – G40.411
      - without status epilepticus – G40.419
    - not intractable – G40.409
      - with status epilepticus – G40.401
      - without status epilepticus – G40.409
- localization-related (focal) (partial)
  - idiopathic – G40.009
    - with seizures of localized onset – G40.009
      - intractable – G40.019
        with status epilepticus – G40.011
        without status epilepticus – G40.019
      - not intractable – G40.009
        with status epilepticus – G40.001
        without status epilepticus – G40.009
  - symptomatic
    - with complex partial seizures – G40.209
      - intractable – G40.219
        with status epilepticus – G40.211
        without status epilepticus – G40.219
      - not intractable – G40.209
        with status epilepticus – G40.201
        without status epilepticus – G40.209
    - with simple partial seizures – G40.109
      - intractable – G40.119
        with status epilepticus – G40.111
        without status epilepticus – G40.119
      - not intractable – G40.109
        with status epilepticus – G40.101
        without status epilepticus – G40.109
- specified NEC – G40.802
  - intractable – G40.804
    - with status epilepticus – G40.803
    - without status epilepticus – G40.804
  - not intractable – G40.802
    - with status epilepticus – G40.801
    - without status epilepticus – G40.802
tonic (-clonic) – see Epilepsy, generalized, specified NEC
twilight – F05
uncinate (gyrus) – see Epilepsy, localization-related, symptomatic, with complex partial seizures
Unverricht (-Lundborg) (familial myoclonic) – see Epilepsy, generalized, idiopathic
visceral – see Epilepsy, specified NEC
visual – see Epilepsy, specified NEC

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.