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ICD-10-CM 2027 diagnosis code

G40.0Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset

Not billable — use a more specific code

G40.0 is a header code, so it can't be reported by itself. Choose one of the 2 more specific codes beneath it.Short description: Local-rel (focal) idio epilepsy w seizures of loc onset

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About G40.0

G40.0 is the ICD-10-CM diagnosis code for Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset. It belongs to category G40 (epilepsy and recurrent seizures), block G40-G47 (episodic and paroxysmal disorders) and chapter 6 (diseases of the nervous system). It is a header code, so it can't be reported by itself; one of its 2 subcodes must be used instead.

Within G40 (epilepsy and recurrent seizures), G40.0 is specifically for Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset. Related codes cover Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with simple partial seizures (G40.1), Localization-related (focal) (partial) symptomatic epilepsy and epileptic syndromes with complex partial seizures (G40.2), generalized idiopathic epilepsy and epileptic syndromes (G40.3), other generalized epilepsy and epileptic syndromes (G40.4), epileptic seizures related to external causes (G40.5), other epilepsy and recurrent seizures (G40.8), epilepsy, unspecified (G40.9), absence epileptic syndrome (G40.A) and 2 more.

To report this condition, pick the subcode that matches the documentation: G40.00 (not intractable) and G40.01 (intractable).

Don't report G40.0 together with the conditions in its Excludes1 note: adult onset localization-related epilepsy (G40.1-, G40.2-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under G40.0

Coding notes

Applicable toConditions and synonyms classified to this code
  • Benign childhood epilepsy with centrotemporal EEG spikes
  • Childhood epilepsy with occipital EEG paroxysms
Excludes1Not coded here — never report together with this code

Notes that apply from higher levels

Instructions written at a parent level also apply to G40.0.

› From G40 Epilepsy and recurrent seizures
Note
  • the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled
Excludes1
  • conversion disorder with seizures (F44.5)
  • convulsions NOS (R56.9)
  • post traumatic seizures (R56.1)
  • seizure (convulsive) NOS (R56.9)
  • seizure of newborn (P90)
Excludes2

Broader instructions also apply from Chapter 6: Diseases of the nervous system.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • No changes since FY2016.

Common questions about G40.0

Is G40.0 billable?

No. G40.0 is a header code. Report one of its more specific subcodes instead.