G83.34 ICD-10-CM Code: Monoplegia, unspecified affecting left nondominant side
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Cerebral palsy and other paralytic syndromes (G80-G83)
G83.34
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMonoplegia, unspecified affecting left nondominant side
Weakness or paralysis affecting one limb on the left side of the body in a person whose right side is dominant (right-handed person with left-side weakness).
Buddy Insight
Monoplegia, unspecified affecting the left nondominant side is the most common partially-specified monoplegia code since most people are right-handed.
CMS-HCC V28
MappedHCC 254
RAF 0.0
CMS-HCC V24
MappedHCC 104
RAF 0.304
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 104
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for G83.34 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G83.34 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G83.34 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for G83.34 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G83.34 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G83.34 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G83.34 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is G83.34 an HCC code?
Yes. G83.34 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 G83.34
For G83.34to 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 G83.34 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G83.34 is the ICD-10-CM diagnosis code for monoplegia, unspecified affecting left nondominant side. Weakness or paralysis affecting one limb on the left side of the body in a person whose right side is dominant (right-handed person with left-side weakness). G83.34 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, G83.34 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, G83.34 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.
Identify the specific limb involved (arm or leg) in the medical record. Because G83.34 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 G83.34 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Identify the specific limb involved (arm or leg) in the medical record
- •This is the most common monoplegia presentation; verify dominance is documented
Clinical Significance
Monoplegia, unspecified affecting the left nondominant side is the most common partially-specified monoplegia code since most people are right-handed. This captures paralysis of one limb on the left side without identifying whether the arm or leg is affected. As the most frequently encountered variant, this code has significant aggregate impact on risk adjustment. Provider query for limb type should be standard practice.
Documentation Requirements
- ✓Documentation of monoplegia affecting the left side
- ✓Right-side dominance documented (left is nondominant)
- ✓Underlying etiology
- ✓Functional impact assessment
- ✓Active treatment plan
Commonly Confused Codes
- •G83.14 Monoplegia of lower limb, left nondominant: use when the leg is identified
- •G83.24 Monoplegia of upper limb, left nondominant: use when the arm is identified
- •G83.32 Monoplegia, unspecified, left dominant: left side in a left-handed person
- •G81.94 Hemiplegia, unspecified, left nondominant: both arm and leg involved