G40.901
BillableEpilepsy, unspecified, 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 G40.901 an HCC code?
Yes. G40.901 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 G40.901
For G40.901 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 G40.901 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.901 is the ICD-10-CM diagnosis code for epilepsy, unspecified, not intractable, with status epilepticus. Epilepsy of unknown type that is not resistant to medication, currently experiencing status epilepticus (prolonged or repeated seizures without recovery). G40.901 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, G40.901 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, G40.901 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.
Status epilepticus is a medical emergency; ensure documentation clearly indicates this acute condition. Because G40.901 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 G40.901 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Status epilepticus is a medical emergency; ensure documentation clearly indicates this acute condition
- •The '901' ending indicates both unspecified epilepsy AND status epilepticus occurring together
Clinical Significance
Unspecified epilepsy with status epilepticus indicates a patient in a life-threatening prolonged seizure state whose epilepsy type has not been determined. This typically occurs in emergency settings where the immediate priority is terminating the seizure rather than classifying the epilepsy type. Status epilepticus requires emergent treatment regardless of epilepsy classification.
Documentation Requirements
- ✓Documentation of active status epilepticus during the encounter
- ✓Statement that epilepsy type is unspecified or undetermined
- ✓Confirmation seizures are not intractable (medication-responsive) or intractability is unknown
- ✓Emergency interventions provided (IV benzodiazepines, loading doses of antiepileptics)
- ✓Plan for diagnostic workup to determine epilepsy type
- ✓Duration and characteristics of status epilepticus
Commonly Confused Codes
- •G40.909 — Unspecified epilepsy WITHOUT status epilepticus
- •G40.911 — Unspecified epilepsy, INTRACTABLE, with status epilepticus
- •G40.801 — Other epilepsy with status epilepticus; slightly more specific
- •G40.401 — Other generalized epilepsy with status epilepticus; use when generalized type is known
- •R56.9 — Unspecified convulsions; for single seizure, not established epilepsy