G40.824
BillableEpileptic spasms, intractable, without status epilepticus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G40.824 an HCC code?
Yes. G40.824 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 G40.824
For G40.824 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 G40.824 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G40.824 is the ICD-10-CM diagnosis code for epileptic spasms, intractable, without status epilepticus. Epileptic spasms that do not respond well to medication, not currently in a prolonged seizure state. G40.824 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, G40.824 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, G40.824 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.
Document evidence of drug-resistant epilepsy (failed medication trials) to justify the intractable designation. Because G40.824 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 G40.824 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document evidence of drug-resistant epilepsy (failed medication trials) to justify the intractable designation
- •Confirm absence of status epilepticus in current documentation
Clinical Significance
Intractable epileptic spasms without status epilepticus is a common presentation in drug-resistant infantile spasms or ongoing epileptic spasm disorder. These patients have failed standard treatments and continue to have spasms that impact development. Many are evaluated for epilepsy surgery, particularly when a focal lesion like tuberous sclerosis is identified.
Documentation Requirements
- ✓Documentation of epileptic spasms diagnosis
- ✓Evidence of intractability with failed medication trials
- ✓Absence of status epilepticus at the encounter
- ✓Complete treatment history including ACTH, vigabatrin, and other agents tried
- ✓Surgical evaluation results if applicable
- ✓Developmental and cognitive assessment
- ✓Underlying etiology if identified
Commonly Confused Codes
- •G40.822 — Epileptic spasms, NOT intractable, without status epilepticus
- •G40.823 — Epileptic spasms, intractable, WITH status epilepticus
- •G40.814 — Lennox-Gastaut, intractable; may evolve from spasms
- •G40.804 — Other epilepsy, intractable; less specific
- •G40.42 — CDKL5 Deficiency Disorder; use when CDKL5 mutation is confirmed