G40.823
BillableEpileptic spasms, intractable, with status epilepticus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G40.823 an HCC code?
Yes. G40.823 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 G40.823
For G40.823 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 G40.823 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.823 is the ICD-10-CM diagnosis code for epileptic spasms, intractable, with status epilepticus. Epileptic spasms that do not respond well to medication, currently experiencing a prolonged seizure state (status epilepticus). G40.823 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, G40.823 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, G40.823 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 documentation shows failed trials of multiple anti-seizure medications to support 'intractable' status. Because G40.823 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 G40.823 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm documentation shows failed trials of multiple anti-seizure medications to support 'intractable' status
- •Ensure status epilepticus is explicitly documented as present during the encounter
Clinical Significance
Intractable epileptic spasms with status epilepticus represents one of the most severe pediatric epilepsy presentations. Drug-resistant spasms in status epilepticus carry high risk of brain injury, developmental regression, and mortality. These patients often require aggressive treatment including high-dose ACTH, combination therapy, and may be urgent surgical candidates.
Documentation Requirements
- ✓Documentation of epileptic spasms with intractability (failed medication trials)
- ✓Active status epilepticus during the encounter
- ✓List of medications attempted and failed (ACTH, vigabatrin, etc.)
- ✓Emergency interventions and ICU management
- ✓Etiology workup results (genetic, structural, metabolic)
- ✓Surgical evaluation documentation if applicable
Commonly Confused Codes
- •G40.821 — Epileptic spasms with status epilepticus but NOT intractable
- •G40.824 — Epileptic spasms, intractable, WITHOUT status epilepticus
- •G40.813 — Lennox-Gastaut, intractable, with status epilepticus; distinct syndrome
- •G40.833 — Dravet syndrome, intractable, with status epilepticus; genetic epilepsy
- •G40.803 — Other epilepsy, intractable, with status epilepticus; less specific