G40.B19
BillableJuvenile myoclonic epilepsy, 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.B19 an HCC code?
Yes. G40.B19 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.B19
For G40.B19 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.B19 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.B19 is the ICD-10-CM diagnosis code for juvenile myoclonic epilepsy, intractable, without status epilepticus. Juvenile myoclonic epilepsy that does not respond adequately to medication, but the patient is not currently experiencing prolonged or repeated seizure activity. G40.B19 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.B19 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.B19 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.
Confirm intractability is documented (seizures not controlled despite medication trials). Because G40.B19 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.B19 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm intractability is documented (seizures not controlled despite medication trials)
- •Verify absence of status epilepticus at the time of encounter or documentation period
Clinical Significance
Intractable juvenile myoclonic epilepsy without status epilepticus indicates ongoing drug-resistant seizures in a patient with JME who is not in acute crisis. Since JME typically responds to appropriate medication, intractability should prompt review of the medication regimen for inappropriate agents and assessment for medication adherence, particularly in the adolescent population.
Documentation Requirements
- ✓Confirmed JME diagnosis
- ✓Documentation of intractability with list of failed medications
- ✓Absence of status epilepticus
- ✓Verification that appropriate JME medications were tried (valproate, levetiracetam)
- ✓Assessment of medication adherence
- ✓Current seizure frequency and impact on daily life