2021 ICD-10-CM Diagnosis Code G40.A

Absence epileptic syndrome

    2016 2017 2018 2019 2020 2021 Non-Billable/Non-Specific Code
  • G40.A should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
  • The 2021 edition of ICD-10-CM G40.A became effective on October 1, 2020.
  • This is the American ICD-10-CM version of G40.A - other international versions of ICD-10 G40.A may differ.
Applicable To
  • Childhood absence epilepsy [pyknolepsy]
  • Juvenile absence epilepsy
  • Absence epileptic syndrome, NOS
The following code(s) above G40.A contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to G40.A:
  • G00-G99
    2021 ICD-10-CM Range G00-G99

    Diseases of the nervous system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    Diseases of the nervous system
  • G40
    ICD-10-CM Diagnosis Code G40

    Epilepsy and recurrent seizures

      2016 2017 2018 2019 2020 2021 Non-Billable/Non-Specific Code
    • the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled
    Type 1 Excludes
    • conversion disorder with seizures (F44.5)
    • convulsions NOS (R56.9)
    • post traumatic seizures (R56.1)
    • seizure (convulsive) NOS (R56.9)
    • seizure of newborn (P90)
    Type 2 Excludes
    Epilepsy and recurrent seizures
Clinical Information
  • A childhood seizure disorder 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 characterized by very brief episodes of sudden cessation of activity, usually associated with eye blinking. There is no loss of the muscle tone.
  • Generalized seizure that manifests in a form of a brief episode of impairment of consciousness with or without accompanying motor phenomena such as clonic-tonic components, automatisms, or autonomic components.
  • The seizure seen in absence epilepsy, consisting of a sudden momentary break in consciousness of thought or activity, often accompanied by automatisms or clonic movements, especially of the eyelids. (cdrh)
Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
  • 2020 (effective 10/1/2019): No change
  • 2021 (effective 10/1/2020): No change

Diagnosis Index entries containing back-references to G40.A:
  • Seizure(s) R56.9
    - see also Convulsions
    ICD-10-CM Diagnosis Code R56.9

    Unspecified convulsions

      2016 2017 2018 2019 2020 2021 Billable/Specific Code
    Applicable To
    • Convulsion disorder
    • Fit NOS
    • Recurrent convulsions
    • Seizure(s) (convulsive) NOS

ICD-10-CM Codes Adjacent To G40.A
G40.21 Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures, intractable
G40.211 …… with status epilepticus
G40.219 …… without status epilepticus
G40.3 Generalized idiopathic epilepsy and epileptic syndromes
G40.30 Generalized idiopathic epilepsy and epileptic syndromes, not intractable
G40.301 …… with status epilepticus
G40.309 …… without status epilepticus
G40.31 Generalized idiopathic epilepsy and epileptic syndromes, intractable
G40.311 …… with status epilepticus
G40.319 …… without status epilepticus
G40.A Absence epileptic syndrome
G40.A0 Absence epileptic syndrome, not intractable
G40.A01 …… with status epilepticus
G40.A09 …… without status epilepticus
G40.A1 Absence epileptic syndrome, intractable
G40.A11 …… with status epilepticus
G40.A19 …… without status epilepticus
G40.B Juvenile myoclonic epilepsy [impulsive petit mal]
G40.B0 Juvenile myoclonic epilepsy, not intractable
G40.B01 …… with status epilepticus
G40.B09 …… without status epilepticus

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.