G40.31 – Generalized idiopathic epilepsy and epileptic syndromes, intractable

ICD-10-CM 2027 diagnosis code · Episodic and paroxysmal disorders

Non-billable header

ICD-10-CM code G40.31
Code
G40.31 (claims format: G4031)
Description
Generalized idiopathic epilepsy and epileptic syndromes, intractable
Short description
Generalized idiopathic epilepsy, intractable
Billable
No – use a more specific code below
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
6. Diseases of the nervous system (G00-G99)
Block
G40-G47 Episodic and paroxysmal disorders
Parent codes
G40 › G40.3

Billable codes under G40.31

G40.31 is a header code and cannot be used on claims. Choose the most specific code:

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

G40 – Epilepsy and recurrent seizures

Excludes1 (not coded here):
  • 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 (not included here):
Notes:
  • the following terms are to be considered equivalent to intractable: pharmacoresistant (pharmacologically resistant), treatment resistant, refractory (medically) and poorly controlled

G40.3 – Generalized idiopathic epilepsy and epileptic syndromes

Code also:
  • MERRF syndrome, if applicable (E88.42)

Related codes in G40.3

Frequently asked questions

What is ICD-10 code G40.31?

G40.31 is the ICD-10-CM code for generalized idiopathic epilepsy and epileptic syndromes, intractable, in the block G40-G47 (Episodic and paroxysmal disorders).

Is G40.31 a billable code?

No. G40.31 is a header code with more specific child codes; report one of the billable codes listed above.

What category does G40.31 belong to?

It belongs to category G40 – Epilepsy and recurrent seizures.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.