G80.3
BillableAthetoid cerebral palsy
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G80.3 an HCC code?
Yes. G80.3 maps to Cerebral Palsy, Except Quadriplegic under the CMS-HCC V28 risk adjustment model (and Cerebral Palsy 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 G80.3
For G80.3 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 G80.3 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G80.3 is the ICD-10-CM diagnosis code for athetoid cerebral palsy. A type of cerebral palsy characterized by involuntary, uncontrolled movements and fluctuating muscle tone rather than stiffness. G80.3 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering cerebral palsy and other paralytic syndromes (g80-g83).
Under the CMS-HCC V28 risk adjustment model, G80.3 maps to Cerebral Palsy, Except Quadriplegic (HCC 192) with a community, non-dual, aged base RAF weight of 0.368. Under the older CMS-HCC V24 model, G80.3 maps to Cerebral Palsy (HCC 74) with a community, non-dual, aged base RAF weight of 0.000. 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.
Athetoid cerebral palsy presents with writhing, twisting movements; document the pattern and frequency of involuntary movements. Because G80.3 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 G80.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Athetoid cerebral palsy presents with writhing, twisting movements; document the pattern and frequency of involuntary movements
- •Often associated with hearing problems and speech difficulties; code these conditions if present
Clinical Significance
Athetoid (dyskinetic) cerebral palsy is characterized by involuntary, writhing movements and fluctuating muscle tone rather than the constant stiffness seen in spastic types. It is most commonly caused by bilirubin encephalopathy or asphyxia-related basal ganglia injury. These patients often have normal intelligence but severe motor impairment, creating unique challenges for communication, feeding, and daily functioning.
Documentation Requirements
- ✓Diagnosis of cerebral palsy with athetoid/dyskinetic type specified
- ✓Description of involuntary movement patterns: athetosis, chorea, dystonia
- ✓Underlying etiology when known: kernicterus, hypoxic-ischemic encephalopathy
- ✓Speech and communication assessment: dysarthria severity, alternative communication needs
- ✓Feeding and swallowing function evaluation
- ✓Cognitive assessment: intelligence is often preserved, document accurately
- ✓Current therapy: medications for movement control, physical/occupational/speech therapy