G93.45
BillableDevelopmental and epileptic encephalopathy
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G93.45 an HCC code?
Yes. G93.45 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 G93.45
For G93.45 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 G93.45 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G93.45 is the ICD-10-CM diagnosis code for developmental and epileptic encephalopathy. A severe brain disorder that begins in childhood or infancy, characterized by developmental delays and frequent seizures. G93.45 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering other disorders of the nervous system (g89-g99).
Under the CMS-HCC V28 risk adjustment model, G93.45 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, G93.45 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 the age of onset and the specific genetic mutation if identified through testing. Because G93.45 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 G93.45 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the age of onset and the specific genetic mutation if identified through testing
- •This code encompasses multiple genetic forms of developmental and epileptic encephalopathy
Clinical Significance
Developmental and epileptic encephalopathy encompasses a group of severe epilepsy syndromes where epileptic activity itself contributes to progressive cognitive and behavioral deterioration beyond what the underlying brain pathology alone would cause. These conditions typically present in infancy or childhood with refractory seizures and developmental regression. They represent some of the most treatment-resistant and resource-intensive epilepsy conditions.
Documentation Requirements
- ✓Electroencephalography findings documenting epileptiform activity consistent with epileptic encephalopathy
- ✓Documentation of developmental regression or plateau temporally associated with seizure onset
- ✓Specific syndrome identified when possible (e.g., West syndrome, Lennox-Gastaut, Dravet syndrome)
- ✓Genetic testing results if performed (SCN1A, CDKL5, STXBP1, and others)
- ✓Current antiepileptic drug regimen and treatment response documentation
- ✓Developmental assessment documenting cognitive and functional impact
Code Also
- , if applicable, associated disorders such as:
- developmental disorders of scholastic skills (F81.-)
- developmental disorder of speech and language (F80.-)
- epilepsy, by specific type (G40.-)
- intellectual disabilities (F70-F79)
- other neurodevelopmental disorder (F88)
- pervasive developmental disorders (F84.-)
Commonly Confused Codes
- •G40.A09 — Absence epileptic syndrome, not intractable: less severe epilepsy syndrome without encephalopathy
- •G40.80 — Other epilepsy: simpler epilepsy without the developmental/encephalopathic component
- •G40.42 — Cyclical vomiting in epilepsy: specific epilepsy manifestation without encephalopathy
- •F84.0 — Autistic disorder: may coexist but represents a developmental disorder without the epileptic encephalopathy component