G40.919 ICD-10-CM Code: Epilepsy, unspecified, intractable, without status epilepticus
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Episodic and paroxysmal disorders (G40-G47)
G40.919
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceEpilepsy, unspecified, intractable, without status epilepticus
Epilepsy of unknown type that is resistant to medication, without current status epilepticus.
Buddy Insight
Unspecified epilepsy, intractable, without status epilepticus identifies patients with drug-resistant seizures of undetermined epilepsy type who are not in acute crisis.
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
Official- Intractable seizure disorder NOS
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G40.919 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G40.919 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G40.919 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G40.919 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G40.919 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G40.919 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 G40.919 an HCC code?
Yes. G40.919 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 G40.919
For G40.919to 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 G40.919 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G40.919 is the ICD-10-CM diagnosis code for epilepsy, unspecified, intractable, without status epilepticus. Epilepsy of unknown type that is resistant to medication, without current status epilepticus. G40.919 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, G40.919 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, G40.919 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 failed medication trials to justify the 'intractable' designation. Because G40.919 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 G40.919 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document failed medication trials to justify the 'intractable' designation
- •Distinguish between intractable epilepsy (drug-resistant) and uncontrolled seizures due to non-compliance
Clinical Significance
Unspecified epilepsy, intractable, without status epilepticus identifies patients with drug-resistant seizures of undetermined epilepsy type who are not in acute crisis. These patients have ongoing uncontrolled seizures despite medication and would benefit from comprehensive evaluation to determine epilepsy syndrome for targeted treatment approaches.
Documentation Requirements
- ✓Documentation of intractable/drug-resistant epilepsy
- ✓List of medications tried and failed
- ✓Absence of status epilepticus at the encounter
- ✓Current seizure frequency and impact on functioning
- ✓Referral or plan for comprehensive epilepsy evaluation
- ✓Current medication regimen
Commonly Confused Codes
- •G40.909 — Unspecified epilepsy, NOT intractable; seizures controlled
- •G40.911 — Unspecified epilepsy, intractable, WITH status epilepticus
- •G40.804 — Other epilepsy, intractable; slightly more specific
- •G40.419 — Other generalized epilepsy, intractable; use when type is known
- •G40.814 — Lennox-Gastaut, intractable; use when syndrome is confirmed