G40.A01
BillableAbsence epileptic syndrome, not 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.A01 an HCC code?
Yes. G40.A01 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.A01
For G40.A01to 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.A01 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.A01 is the ICD-10-CM diagnosis code for absence epileptic syndrome, not intractable, with status epilepticus. Absence epilepsy (characterized by brief lapses in consciousness) that responds to medication, currently experiencing status epilepticus. G40.A01 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.A01 maps to Seizure Disorders and Convulsions (HCC 201) with a community, non-dual, aged base RAF weight of 0.245. Under the older V24 model, G40.A01 mapped to the same category but with a base RAF weight of 0.220 — 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.
Absence seizures are typically brief (5-30 seconds) with sudden onset and offset. Because G40.A01 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.A01 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Absence seizures are typically brief (5-30 seconds) with sudden onset and offset
- •Status epilepticus in absence epilepsy may present as continuous or frequent absence seizures
Clinical Significance
Absence epileptic syndrome with status epilepticus represents a prolonged or continuously recurring absence seizure state. Absence status epilepticus may present as prolonged confusion or altered awareness without convulsive activity, making it easy to miss. This is typically a childhood-onset epilepsy with generalized 3 Hz spike-and-wave discharges on EEG.
Documentation Requirements
- ✓Confirmed absence epilepsy diagnosis with characteristic EEG findings (3 Hz spike-and-wave)
- ✓Documentation of absence status epilepticus (prolonged or frequent absence seizures without full recovery)
- ✓Statement that seizures respond to medication (not intractable)
- ✓Emergency interventions if applicable
- ✓Age of onset and seizure frequency history
- ✓Current antiepileptic medication (typically ethosuximide, valproic acid, or lamotrigine)
Commonly Confused Codes
- •G40.A09 — Absence epilepsy, not intractable, WITHOUT status epilepticus
- •G40.A11 — Absence epilepsy, INTRACTABLE, with status epilepticus
- •G40.401 — Other generalized epilepsy with status epilepticus; absence epilepsy is a specific subtype
- •G40.B01 — Juvenile myoclonic epilepsy with status epilepticus; different generalized epilepsy syndrome
- •R40.4 — Transient alteration of awareness; non-epileptic episodes