G81.10
BillableSpastic hemiplegia affecting unspecified side
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G81.10 an HCC code?
Yes. G81.10 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 G81.10
For G81.10to 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 G81.10 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G81.10 is the ICD-10-CM diagnosis code for spastic hemiplegia affecting unspecified side. This code describes a condition where one side of the body is paralyzed or severely weakened with stiff, tight muscles due to a brain or spinal cord injury. The specific side of the body affected (left or right) is not documented in the medical record. G81.10 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, G81.10 maps to Hemiplegia/Hemiparesis (HCC 253) with a community, non-dual, aged base RAF weight of 0.387. Under the older V24 model, G81.10 mapped to the same category but with a base RAF weight of 0.437 — 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.
Query the provider to determine if the hemiplegia affects the right or left side, as codes G81.11 (right) and G81.12 (left) are more specific and preferred for accurate documentation. Because G81.10 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 G81.10 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Query the provider to determine if the hemiplegia affects the right or left side, as codes G81.11 (right) and G81.12 (left) are more specific and preferred for accurate documentation
- •Verify the underlying cause (stroke, brain injury, etc.) and code it as the primary diagnosis, as hemiplegia is typically a manifestation of another condition
Clinical Significance
Spastic hemiplegia affecting an unspecified side represents a common post-stroke or brain injury pattern with increased muscle tone, stiffness, and weakness on one side of the body. Spasticity drives significant healthcare resource use including botulinum toxin injections, anti-spasticity medications, specialized rehabilitation, and sometimes surgical intervention. This is a documentation improvement opportunity since the affected side should be identifiable.
Documentation Requirements
- ✓Documentation of hemiplegia with spastic (increased tone) presentation
- ✓Neurological examination findings showing hypertonicity, hyperreflexia, clonus
- ✓Underlying etiology documented and coded separately
- ✓Functional impact on mobility and activities of daily living
- ✓Spasticity management plan (medications, therapy, injections)
- ✓Status as active, ongoing condition
Commonly Confused Codes
- •G81.00 Flaccid hemiplegia affecting unspecified side — flaccid has low tone; spastic has high tone
- •G81.90 Hemiplegia, unspecified affecting unspecified side — use only when neither spastic nor flaccid is documented
- •G81.11-G81.14 Spastic hemiplegia with laterality — preferred codes when side and dominance are documented
- •I69.151-I69.154 Hemiplegia following cerebral infarction — use for stroke-related spastic hemiplegia