G40.834
BillableDravet syndrome, intractable, without status epilepticus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G40.834 an HCC code?
Yes. G40.834 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 G40.834
For G40.834 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 G40.834 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.834 is the ICD-10-CM diagnosis code for dravet syndrome, intractable, without status epilepticus. Dravet syndrome (a severe genetic epilepsy starting in infancy) that does not respond well to medication, not currently in a prolonged seizure state. G40.834 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, G40.834 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, G40.834 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.
Ensure genetic confirmation or clinical diagnosis of Dravet syndrome is documented in the record. Because G40.834 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 G40.834 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure genetic confirmation or clinical diagnosis of Dravet syndrome is documented in the record
- •Document the intractable nature with evidence of failed anti-seizure medication trials
Clinical Significance
Dravet syndrome, intractable, without status epilepticus captures the chronic management phase of this severe genetic epilepsy. Dravet syndrome is almost always intractable, making this the most common Dravet code. These patients require complex multi-drug regimens avoiding sodium channel blockers, and face ongoing risks of SUDEP, cognitive decline, and gait deterioration throughout life.
Documentation Requirements
- ✓Confirmed Dravet syndrome diagnosis (SCN1A mutation or clinical criteria)
- ✓Documentation of intractability
- ✓Absence of status epilepticus at the encounter
- ✓Current medication regimen avoiding contraindicated sodium channel blockers
- ✓Seizure diary or frequency documentation
- ✓Developmental and cognitive assessments
- ✓SUDEP risk discussion and seizure safety plan