G40.833
BillableDravet syndrome, intractable, with status epilepticus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G40.833 an HCC code?
Yes. G40.833 maps to Seizure Disorders and Convulsions under the CMS-HCC V28 risk adjustment model (and Seizure Disorders and Convulsions under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
MEAT Criteria for G40.833
For G40.833 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically — it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G40.833 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.833 is the ICD-10-CM diagnosis code for dravet syndrome, intractable, with status epilepticus. Dravet syndrome (a severe genetic epilepsy starting in infancy) that does not respond well to medication, currently experiencing a prolonged seizure state. G40.833 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering episodic and paroxysmal disorders (g40-g47).
Under the CMS-HCC V28 risk adjustment model, G40.833 maps to Seizure Disorders and Convulsions (HCC 201) with a community, non-dual, aged base RAF weight of 0.262. Under the older V24 model, G40.833 mapped to the same category but with a base RAF weight of 0.244 — V28 recalibrated weights across the entire model. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
Verify genetic testing or clinical diagnosis of Dravet syndrome is documented. Because G40.833 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G40.833 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify genetic testing or clinical diagnosis of Dravet syndrome is documented
- •Confirm status epilepticus is present and document the intractable nature with failed medication trials
Clinical Significance
Dravet syndrome (severe myoclonic epilepsy of infancy) is a rare, catastrophic genetic epilepsy caused primarily by SCN1A gene mutations. Intractable Dravet syndrome with status epilepticus is a life-threatening emergency, as these patients are highly susceptible to prolonged febrile and afebrile seizures. Dravet syndrome carries risk of sudden unexpected death in epilepsy (SUDEP) and requires lifelong specialized neurological care.
Documentation Requirements
- ✓Confirmed Dravet syndrome diagnosis (clinical or genetic confirmation of SCN1A mutation)
- ✓Documentation of intractability with list of failed antiepileptic drugs
- ✓Active status epilepticus during the encounter
- ✓Emergency interventions provided
- ✓Genetic testing results if available
- ✓Current medication regimen (noting contraindicated sodium channel blockers)
- ✓SUDEP risk discussion documentation