What is ICD-10 code G83.10?

G83.10 is the ICD-10-CM diagnosis code for Monoplegia of lower limb affecting unspecified side. Weakness or paralysis affecting one leg, but the specific side (left or right) is not documented or specified in the medical record. G83.10 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G83.10 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. G83.10 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. G83.10 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for G83.10?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. For G83.10, V28 maps to Monoplegia, Other Paralytic Syndromes at RAF 0.000 while V24 mapped to Monoplegia, Other Paralytic Syndromes at RAF 0.304. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting G83.10?

Query the provider to determine which leg is affected (left or right) to assign the more specific codes G83.11 or G83.12 Use this unspecified code only when laterality cannot be determined from available documentation Because G83.10 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

G83.10: Monoplegia of lower limb affecting

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupG83.10Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Cerebral palsy and other paralytic syndromes (G80-G83)

G83.10

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Monoplegia of lower limb affecting unspecified side

Weakness or paralysis affecting one leg, but the specific side (left or right) is not documented or specified in the medical record.

Buddy Insight

Monoplegia of the lower limb affecting an unspecified side indicates paralysis of one leg without laterality documentation.

CMS-HCC V28

Mapped

HCC 254

Monoplegia, Other Paralytic S...

RAF 0.0

CMS-HCC V24

Mapped

HCC 104

Monoplegia, Other Paralytic S...

RAF 0.304

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 104

Monoplegia, Other Paralytic S...

RAF 0.0

RXHCC

Not risk-adjusted for this model/period.

RAF 0

Code Trumping

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Code Book Path

Official

G83Other paralytic syndromes

G83.1Monoplegia of lower limb

G83.10Monoplegia of lower limb affecting unspecified side

Inclusion Terms

Official

Paralysis of lower limb

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G83.10 in this effective period.

Related Child Codes

Official

G83.11Monoplegia of lower limb affecting right dominant side

G83.12Monoplegia of lower limb affecting left dominant side

G83.13Monoplegia of lower limb affecting right nondominant side

G83.14Monoplegia of lower limb affecting left nondominant side

Includes

Official

ICD-10-CM does not list Includes notes for G83.10 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

Official

ICD-10-CM does not list Code First sequencing instructions for G83.10 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G83.10 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G83.10 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of monoplegia affecting one lower extremity

Clinical evidence of paralysis or severe weakness isolated to one leg

Underlying etiology (stroke, spinal cord lesion, peripheral nerve injury)

Mobility status and assistive device needs

MEAT Support

HCC Buddy guidance

Documentation of monoplegia affecting one lower extremity

Clinical evidence of paralysis or severe weakness isolated to one leg

Underlying etiology (stroke, spinal cord lesion, peripheral nerve injury)

Mobility status and assistive device needs

Audit Caution

HCC Buddy guidance

Using this unspecified code when the medical record documents which leg is affected

Confusing lower extremity weakness from deconditioning or arthritis with monoplegia from neurological cause

Not querying the provider for laterality to improve code specificity

Failing to distinguish monoplegia from foot drop (M21.37-) which is a specific deformity, not paralysis

Common Mistakes

HCC Buddy guidance

G83.11-G83.14 Monoplegia of lower limb with laterality — preferred when side and dominance are documented

G82.20 Paraplegia — both legs affected, not just one

G81.90 Hemiplegia, unspecified — entire side affected, not just the leg

M62.81 Muscle weakness — weakness may not rise to the level of monoplegia/paralysis

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 G83.10 an HCC code?

Yes. G83.10 maps to Monoplegia, Other Paralytic Syndromes under the CMS-HCC V28 risk adjustment model (and Monoplegia, Other Paralytic Syndromes under V24).

HCC Category Mapping

V28HCC 254, Monoplegia, Other Paralytic Syndromes

0.000

V24HCC 104, Monoplegia, Other Paralytic Syndromes

0.304

ESRDHCC 104, Monoplegia, Other Paralytic Syndromes

0.000

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 G83.10

For G83.10to 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 G83.10 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

G83.10 is the ICD-10-CM diagnosis code for monoplegia of lower limb affecting unspecified side. Weakness or paralysis affecting one leg, but the specific side (left or right) is not documented or specified in the medical record. G83.10 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, G83.10 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, G83.10 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.

Query the provider to determine which leg is affected (left or right) to assign the more specific codes G83.11 or G83.12. Because G83.10 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 G83.10 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 which leg is affected (left or right) to assign the more specific codes G83.11 or G83.12
•Use this unspecified code only when laterality cannot be determined from available documentation

Clinical Significance

Monoplegia of the lower limb affecting an unspecified side indicates paralysis of one leg without laterality documentation. This condition significantly impacts mobility, gait safety, and fall risk. While less functionally devastating than hemiplegia or paraplegia, single leg paralysis still requires assistive devices, physical therapy, and ongoing monitoring. The unspecified side designation represents a documentation improvement opportunity.

Documentation Requirements

✓Documentation of monoplegia affecting one lower extremity
✓Clinical evidence of paralysis or severe weakness isolated to one leg
✓Underlying etiology (stroke, spinal cord lesion, peripheral nerve injury)
✓Mobility status and assistive device needs
✓Fall risk assessment
✓Active treatment or rehabilitation plan

Commonly Confused Codes

•G83.11-G83.14 Monoplegia of lower limb with laterality: preferred when side and dominance are documented
•G82.20 Paraplegia: both legs affected, not just one
•G81.90 Hemiplegia, unspecified: entire side affected, not just the leg
•M62.81 Muscle weakness: weakness may not rise to the level of monoplegia/paralysis
•M54.41 Sciatica, right side: radicular pain, not paralysis