G83.13
BillableMonoplegia of lower limb affecting right nondominant side
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G83.13 an HCC code?
Yes. G83.13 maps to Monoplegia, Other Paralytic Syndromes under the CMS-HCC V28 risk adjustment model (and Monoplegia, Other Paralytic Syndromes 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 G83.13
For G83.13 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 G83.13 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G83.13 is the ICD-10-CM diagnosis code for monoplegia of lower limb affecting right nondominant side. Weakness or paralysis affecting only the right leg in a person whose right side is not their dominant side. G83.13 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, G83.13 maps to Monoplegia, Other Paralytic Syndromes (HCC 254) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G83.13 mapped to the same category but with a base RAF weight of 0.304 — 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.
Confirm the patient's dominant side is documented as left before assigning this nondominant code. Because G83.13 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 G83.13 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm the patient's dominant side is documented as left before assigning this nondominant code
- •Review imaging or neurological exam findings to confirm the monoplegia is due to a specific neurological lesion
Clinical Significance
Monoplegia of the lower limb affecting the right nondominant side occurs in left-dominant individuals who develop paralysis of their right leg. While the nondominant lower extremity is affected, this still creates significant gait and balance challenges. Accurate laterality and dominance coding supports clinical documentation quality and helps differentiate this from the more common left nondominant presentation.
Documentation Requirements
- ✓Documentation of monoplegia of the right lower extremity
- ✓Patient confirmed as left-side dominant (right is nondominant)
- ✓Underlying etiology documented
- ✓Neurological examination findings
- ✓Functional status and mobility assessment
- ✓Active treatment and rehabilitation plan
Commonly Confused Codes
- •G83.11 Monoplegia of lower limb, right dominant — right leg in a right-dominant person
- •G83.14 Monoplegia of lower limb, left nondominant — wrong limb
- •G81.03 Flaccid hemiplegia, right nondominant — both arm and leg on right side affected
- •G83.10 Monoplegia of lower limb, unspecified — when laterality/dominance unknown