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G40.409

G40.409Other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus

Billable / specific codeICD-10-CM

G40.409 is a billable, specific ICD-10-CM code for other generalized epilepsy and epileptic syndromes, not intractable, without status epilepticus. It is valid for submission on a claim.

Excludes1 inherited from the categories above G40.409

These are not written on G40.409, but they bind it: a note on a category applies to every code beneath it. Billing G40.409 with anything listed here is a denial.

Written on G40 Epilepsy and recurrent seizures

  • 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 inherited from the categories above G40.409

Also inherited, and the opposite of Excludes1: these conditions are not part of G40.409, but a patient can have both, so you may code both.

Written on G40 Epilepsy and recurrent seizures

Other codes that can never be billed with G40.409

These codes carry an Excludes1 note pointing at G40.409. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G40.409 alone.

  • G25.3Myoclonus
  • R56Convulsions, not elsewhere classified
  • R56.1Post traumatic seizures

Risk adjustment

G40.409 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 201 Seizure Disorders and Convulsions0.245 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

G40.409 is named in 28 Medicare coverage policies 28 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A54799Billing and Coding: Urine Drug Testing
  • A55001Billing and Coding: Urine Drug Testing
  • A56551Billing and Coding: Visual Fields Testing
  • A56612Billing and Coding: CT of the Head

How G40.409 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G40.409.

  • Myoclonus, myoclonic, myocloniaepileptica
  • Seizuregrand mal
  • Epilepsy, epileptic, epilepsiageneralizedspecified NEC
  • Seizuregrand malnot intractable
  • Epilepsy, epileptic, epilepsiageneralizedspecified NECnot intractable
  • Epilepsy, epileptic, epilepsiasyndromesgeneralizedspecified NEC
  • Seizuregrand malnot intractablewithout status epilepticus
  • Epilepsy, epileptic, epilepsiageneralizedspecified NECnot intractablewithout status epilepticus
  • Epilepsy, epileptic, epilepsiasyndromesgeneralizedspecified NECnot intractable
  • Epilepsy, epileptic, epilepsiasyndromesgeneralizedspecified NECnot intractablewithout status epilepticus

Code history

G40.409 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Related codes at this level

Codes that share G40.40. If G40.409 is not quite right, the correct code is usually one of these.

Questions about G40.409

Is G40.409 a billable ICD-10-CM code?
Yes. G40.409 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G40.409 sit in the tabular list?
Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).
What cannot be coded together with G40.409?
G40.409 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above G40.409 (G40) and apply to it just the same.
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.