MCMCB Pro
G40.843

G40.843KCNQ2-related epilepsy, intractable, with status epilepticus

Billable / specific codeICD-10-CM

G40.843 is a billable, specific ICD-10-CM code for kcnq2-related epilepsy, intractable, with status epilepticus. It is valid for submission on a claim.

Risk adjustment

G40.843 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

G40.843 is named in 7 Medicare coverage policies 7 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A56612Billing and Coding: CT of the Head
  • A56619Billing and Coding: Nerve Conduction Studies and Electromyography
  • A56771Billing and Coding: Special Electroencephalography
  • A56868Billing and Coding: Outpatient Speech Language Pathology

How G40.843 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 G40.843.

  • Epilepsy, epileptic, epilepsiaKCNQ2-relatedintractablewith status epilepticus

Related codes at this level

Codes that share G40.84. If G40.843 is not quite right, the correct code is usually one of these.

Questions about G40.843

Is G40.843 a billable ICD-10-CM code?
Yes. G40.843 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does G40.843 sit in the tabular list?
Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).
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.