G83.12 ICD-10-CM Code: Monoplegia of lower limb affecting left dominant 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)
G83.12
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMonoplegia of lower limb affecting left dominant side
Weakness or paralysis affecting only the left leg in a person whose left side is their dominant side.
Buddy Insight
Monoplegia of the lower limb affecting the left dominant side is an uncommon presentation occurring in left-dominant individuals.
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
Basket needed
Code Book Path
Inclusion Terms
Official- Paralysis of lower limb
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G83.12 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G83.12 in this effective period.
Excludes 1
Official- monoplegia of lower limbs due to sequela of cerebrovascular disease (I69.04-, I69.14-, I69.24-, I69.34-, I69.84-, I69.94-)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G83.12 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G83.12 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G83.12 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 G83.12 an HCC code?
Yes. G83.12 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 G83.12
For G83.12to 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 G83.12 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G83.12 is the ICD-10-CM diagnosis code for monoplegia of lower limb affecting left dominant side. Weakness or paralysis affecting only the left leg in a person whose left side is their dominant side. G83.12 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, G83.12 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, G83.12 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.
Document the patient's handedness or functional dominance in the medical record to support code selection. Because G83.12 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 G83.12 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the patient's handedness or functional dominance in the medical record to support code selection
- •Distinguish between monoplegia (single limb) and hemiplegia (entire side) when reviewing clinical documentation
Clinical Significance
Monoplegia of the lower limb affecting the left dominant side is an uncommon presentation occurring in left-dominant individuals. This code requires documentation of both left leg paralysis and left-side dominance, which for lower extremities may refer to the preferred kicking leg or weight-bearing limb. These patients need ongoing physical therapy and mobility assistance to maintain function and prevent falls.
Documentation Requirements
- ✓Documentation of monoplegia isolated to the left lower extremity
- ✓Left-side dominance confirmed in the medical record
- ✓Underlying etiology documented and coded
- ✓Neurological exam findings
- ✓Functional impact on mobility and balance
- ✓Active treatment plan
Commonly Confused Codes
- •G83.14 Monoplegia of lower limb, left nondominant: left leg in a right-dominant person
- •G83.11 Monoplegia of lower limb, right dominant: right leg, right dominant
- •G81.02 Flaccid hemiplegia, left dominant: both upper and lower left extremities affected
- •G83.10 Monoplegia of lower limb, unspecified: when laterality is unknown