What is ICD-10 code G81.10?

G81.10 is the ICD-10-CM diagnosis code for Spastic hemiplegia affecting unspecified side. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G81.10 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G81.10 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. G81.10 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. G81.10 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 G81.10?

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 G81.10, V28 maps to Hemiplegia/Hemiparesis at RAF 0.000 while V24 mapped to Hemiplegia/Hemiparesis at RAF 0.447. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting G81.10?

Query the provider to determine if the hemiplegia affects the right or left side, as codes G81.11 (right) and G81.12 (left) are more specific and preferred for accurate documentation Verify the underlying cause (stroke, brain injury, etc.) and code it as the primary diagnosis, as hemiplegia is typically a manifestation of another condition Because G81.10 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.

G81.10 ICD-10 Code: Spastic hemiplegia affecting

ICD-10-CM Code View

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

Code lookupG81.10Effective 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)

G81.10

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

Spastic hemiplegia affecting unspecified side

This code describes a condition where one side of the body is paralyzed or severely weakened with stiff, tight muscles due to a brain or spinal cord injury. The specific side of the body affected (left or right) is not documented in the medical record.

Buddy Insight

Spastic hemiplegia affecting an unspecified side represents a common post-stroke or brain injury pattern with increased muscle tone, stiffness, and weakness on one side of the body.

CMS-HCC V28

Mapped

HCC 253

Hemiplegia/Hemiparesis

RAF 0.0

CMS-HCC V24

Mapped

HCC 103

Hemiplegia/Hemiparesis

RAF 0.447

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 103

Hemiplegia/Hemiparesis

RAF 0.0

RXHCC

Mapped

HCC 207

Hemiplegia/Hemiparesis

RAF 0.0

Code Trumping

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Compare selected patient codes to show trumped or trumps impact.

Code Book Path

Official

G81Hemiplegia and hemiparesis

G81.1Spastic hemiplegia

G81.10Spastic hemiplegia affecting unspecified side

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for G81.10 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G81.10 in this effective period.

Related Child Codes

Official

G81.11Spastic hemiplegia affecting right dominant side

G81.12Spastic hemiplegia affecting left dominant side

G81.13Spastic hemiplegia affecting right nondominant side

G81.14Spastic hemiplegia affecting left nondominant side

Includes

Official

ICD-10-CM does not list Includes notes for G81.10 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G81.10 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G81.10 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G81.10 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G81.10 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation of hemiplegia with spastic (increased tone) presentation

Neurological examination findings showing hypertonicity, hyperreflexia, clonus

Underlying etiology documented and coded separately

Functional impact on mobility and activities of daily living

MEAT Support

HCC Buddy guidance

Documentation of hemiplegia with spastic (increased tone) presentation

Neurological examination findings showing hypertonicity, hyperreflexia, clonus

Underlying etiology documented and coded separately

Functional impact on mobility and activities of daily living

Audit Caution

HCC Buddy guidance

Not querying the provider for laterality information to allow a more specific code

Using this code for acute stroke presentations instead of acute stroke codes with manifestation characters

Confusing spasticity (velocity-dependent resistance) with rigidity (constant resistance, as in Parkinson disease)

Failing to code the underlying cause alongside the spastic hemiplegia

Common Mistakes

HCC Buddy guidance

G81.00 Flaccid hemiplegia affecting unspecified side — flaccid has low tone; spastic has high tone

G81.90 Hemiplegia, unspecified affecting unspecified side — use only when neither spastic nor flaccid is documented

G81.11-G81.14 Spastic hemiplegia with laterality — preferred codes when side and dominance are documented

I69.151-I69.154 Hemiplegia following cerebral infarction — use for stroke-related spastic hemiplegia

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 G81.10 an HCC code?

Yes. G81.10 maps to Hemiplegia/Hemiparesis under the CMS-HCC V28 risk adjustment model (and Hemiplegia/Hemiparesis under V24).

HCC Category Mapping

V28HCC 253, Hemiplegia/Hemiparesis

0.000

V24HCC 103, Hemiplegia/Hemiparesis

0.447

ESRDHCC 103, Hemiplegia/Hemiparesis

0.000

RxHCCHCC 207, Hemiplegia/Hemiparesis

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 G81.10

For G81.10to 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 G81.10 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

G81.10 is the ICD-10-CM diagnosis code for spastic hemiplegia affecting unspecified side. This code describes a condition where one side of the body is paralyzed or severely weakened with stiff, tight muscles due to a brain or spinal cord injury. The specific side of the body affected (left or right) is not documented in the medical record. G81.10 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, G81.10 maps to Hemiplegia/Hemiparesis (HCC 253) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, G81.10 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.

Query the provider to determine if the hemiplegia affects the right or left side, as codes G81.11 (right) and G81.12 (left) are more specific and preferred for accurate documentation. Because G81.10 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 G81.10 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 if the hemiplegia affects the right or left side, as codes G81.11 (right) and G81.12 (left) are more specific and preferred for accurate documentation
•Verify the underlying cause (stroke, brain injury, etc.) and code it as the primary diagnosis, as hemiplegia is typically a manifestation of another condition

Clinical Significance

Spastic hemiplegia affecting an unspecified side represents a common post-stroke or brain injury pattern with increased muscle tone, stiffness, and weakness on one side of the body. Spasticity drives significant healthcare resource use including botulinum toxin injections, anti-spasticity medications, specialized rehabilitation, and sometimes surgical intervention. This is a documentation improvement opportunity since the affected side should be identifiable.

Documentation Requirements

✓Documentation of hemiplegia with spastic (increased tone) presentation
✓Neurological examination findings showing hypertonicity, hyperreflexia, clonus
✓Underlying etiology documented and coded separately
✓Functional impact on mobility and activities of daily living
✓Spasticity management plan (medications, therapy, injections)
✓Status as active, ongoing condition

Commonly Confused Codes

•G81.00 Flaccid hemiplegia affecting unspecified side: flaccid has low tone; spastic has high tone
•G81.90 Hemiplegia, unspecified affecting unspecified side: use only when neither spastic nor flaccid is documented
•G81.11-G81.14 Spastic hemiplegia with laterality: preferred codes when side and dominance are documented
•I69.151-I69.154 Hemiplegia following cerebral infarction: use for stroke-related spastic hemiplegia