G81.00
BillableFlaccid hemiplegia affecting unspecified side
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G81.00 an HCC code?
Yes. G81.00 maps to Hemiplegia/Hemiparesis under the CMS-HCC V28 risk adjustment model (and Hemiplegia/Hemiparesis 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 G81.00
For G81.00to 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 G81.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G81.00 is the ICD-10-CM diagnosis code for flaccid hemiplegia affecting unspecified side. Weakness or paralysis affecting one side of the body with floppy, loose muscle tone when the affected side is not specified. G81.00 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, G81.00 maps to Hemiplegia/Hemiparesis (HCC 253) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G81.00 mapped to the same category but with a base RAF weight of 0.447 — 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.
Flaccid hemiplegia indicates low muscle tone; distinguish from spastic hemiplegia which has high muscle tone. Because G81.00 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 G81.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Flaccid hemiplegia affecting an unspecified side represents significant neurological deficit with loss of muscle tone on one side of the body, typically as a sequela of stroke or brain injury. This condition profoundly impacts independence, mobility, and quality of life, requiring ongoing rehabilitation, assistive devices, and caregiver support. Accurate coding is essential for predicting healthcare resource needs.
Documentation Requirements
- ✓Documentation of hemiplegia or hemiparesis with flaccid (low tone) presentation
- ✓Underlying etiology (stroke, traumatic brain injury, tumor, etc.)
- ✓Neurological examination findings confirming flaccid tone
- ✓Functional impact on mobility and activities of daily living
- ✓Current treatment plan (physical therapy, occupational therapy, assistive devices)
- ✓Status as ongoing condition being actively managed
Commonly Confused Codes
- •G81.10 Spastic hemiplegia affecting unspecified side — spastic has high muscle tone; flaccid has low tone
- •G81.90 Hemiplegia, unspecified affecting unspecified side — use when neither flaccid nor spastic is documented
- •G81.01-G81.04 Flaccid hemiplegia with laterality — use when dominant/nondominant side is specified
- •I69.051-I69.054 Hemiplegia following cerebrovascular disease — use the I69 sequelae codes when hemiplegia is specifically documented as a sequela of stroke