G81.13
BillableSpastic hemiplegia affecting right nondominant side
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G81.13 an HCC code?
Yes. G81.13 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 G81.13
For G81.13to 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 G81.13 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G81.13 is the ICD-10-CM diagnosis code for spastic hemiplegia affecting right nondominant side. Weakness or loss of movement on one side of the body (right side) with tight, stiff muscles, typically resulting from stroke or brain injury, in a person whose right side is their non-dominant side. G81.13 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, G81.13 maps to Hemiplegia/Hemiparesis (HCC 253) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G81.13 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.
Ensure documentation confirms spastic type and right nondominant status. Because G81.13 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 G81.13 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation confirms spastic type and right nondominant status
- •Code the underlying cause separately for complete documentation
Clinical Significance
Spastic hemiplegia affecting the right nondominant side occurs in left-handed patients who develop spasticity and weakness on their right side. While nondominant side involvement preserves some independence in fine motor tasks, spasticity still significantly impacts balance, gait, and bilateral function. This highly specific code indicates comprehensive clinical documentation.
Documentation Requirements
- ✓Documentation of spastic hemiplegia
- ✓Right side identified as affected
- ✓Patient confirmed as left-hand dominant (right is nondominant)
- ✓Underlying etiology documented
- ✓Spasticity assessment findings
- ✓Functional status and limitations
- ✓Active management plan
Commonly Confused Codes
- •G81.11 Spastic hemiplegia affecting right dominant side — right side in a right-handed person
- •G81.03 Flaccid hemiplegia affecting right nondominant side — same laterality/dominance but flaccid
- •G81.93 Hemiplegia, unspecified affecting right nondominant side — when tone type is not documented
- •I69.053 Hemiplegia following cerebrovascular disease, right nondominant — for stroke sequelae