G40.011 ICD-10-CM Code: Localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Episodic and paroxysmal disorders (G40-G47)
G40.011
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceLocalization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus
A type of epilepsy that starts in one area of the brain with no known cause, is difficult to control with medication, and the patient is currently experiencing prolonged seizure activity (status epilepticus).
Buddy Insight
This code captures the most severe presentation of focal idiopathic epilepsy — drug-resistant and currently in status epilepticus.
CMS-HCC V28
MappedHCC 201
RAF 0.262
CMS-HCC V24
MappedHCC 79
RAF 0.244
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 79
RAF 0.0
RXHCC
MappedHCC 163
RAF 0.0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for G40.011 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G40.011 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G40.011 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G40.011 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G40.011 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G40.011 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G40.011 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is G40.011 an HCC code?
Yes. G40.011 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 G40.011
For G40.011to 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 G40.011 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G40.011 is the ICD-10-CM diagnosis code for localization-related (focal) (partial) idiopathic epilepsy and epileptic syndromes with seizures of localized onset, intractable, with status epilepticus. A type of epilepsy that starts in one area of the brain with no known cause, is difficult to control with medication, and the patient is currently experiencing prolonged seizure activity (status epilepticus). G40.011 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, G40.011 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, G40.011 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.
The '01' indicates idiopathic (no known cause) and the final '1' indicates intractable with status epilepticus; ensure all three components are documented. Because G40.011 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 G40.011 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •The '01' indicates idiopathic (no known cause) and the final '1' indicates intractable with status epilepticus; ensure all three components are documented
- •Status epilepticus is a medical emergency; verify this acute condition is documented separately if applicable
Clinical Significance
This code captures the most severe presentation of focal idiopathic epilepsy — drug-resistant and currently in status epilepticus. It represents a neurological emergency in a patient whose seizures are already difficult to control. These patients require intensive care management and carry significantly higher morbidity and mortality risk, warranting accurate coding for resource allocation.
Documentation Requirements
- ✓Documentation confirming focal (localization-related) idiopathic epilepsy
- ✓Documentation of intractable status — multiple medication failures or drug-resistant epilepsy
- ✓Active status epilepticus documented with onset time and interventions
- ✓List of failed antiepileptic medications supporting the intractable designation
- ✓EEG monitoring results if available
- ✓Emergency treatment protocol and response documentation
Commonly Confused Codes
- •G40.019 — Same type, intractable, WITHOUT status epilepticus; use when not in active status epilepticus
- •G40.001 — Same type, NOT intractable, with status epilepticus; when seizures are normally controlled
- •G40.111 — Symptomatic focal epilepsy, intractable, with status epilepticus; has an identified cause
- •G40.311 — Generalized idiopathic epilepsy, intractable, with status epilepticus; generalized rather than focal
- •G40.009 — Same type, not intractable, without status epilepticus; stable well-controlled state