G80.1 ICD-10-CM Code: Spastic diplegic cerebral palsy
HCC Buddy Code Card
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Cerebral palsy and other paralytic syndromes (G80-G83)
G80.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceSpastic diplegic cerebral palsy
A type of cerebral palsy primarily affecting both legs with stiff, rigid muscle tone, while arms are less affected or unaffected.
Buddy Insight
Spastic diplegic cerebral palsy is the most common type of cerebral palsy, primarily affecting the lower extremities with spasticity while relatively sparing the upper body.
CMS-HCC V28
MappedHCC 192
RAF 0.368
CMS-HCC V24
MappedHCC 74
RAF 0.0
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 74
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Spastic cerebral palsy NOS
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for G80.1 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for G80.1 in this effective period.
Excludes 1
Official- hereditary spastic paraplegia (G11.4)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for G80.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for G80.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for G80.1 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 G80.1 an HCC code?
Yes. G80.1 maps to Cerebral Palsy, Except Quadriplegic under the CMS-HCC V28 risk adjustment model (and Cerebral Palsy 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 G80.1
For G80.1to 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 G80.1 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
G80.1 is the ICD-10-CM diagnosis code for spastic diplegic cerebral palsy. A type of cerebral palsy primarily affecting both legs with stiff, rigid muscle tone, while arms are less affected or unaffected. G80.1 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, G80.1 maps to Cerebral Palsy, Except Quadriplegic (HCC 192) with a community, non-dual, aged base RAF weight of 0.368. Under the older CMS-HCC V24 model, G80.1 maps to Cerebral Palsy (HCC 74) with a community, non-dual, aged base RAF weight of 0.000. 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.
Spastic diplegia is the most common form of cerebral palsy; document functional limitations and mobility status. Because G80.1 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 G80.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Spastic diplegia is the most common form of cerebral palsy; document functional limitations and mobility status
- •Often associated with prematurity; review birth history documentation for coding accuracy
Clinical Significance
Spastic diplegic cerebral palsy is the most common type of cerebral palsy, primarily affecting the lower extremities with spasticity while relatively sparing the upper body. It is strongly associated with premature birth and periventricular leukomalacia. These patients require ongoing physical therapy, orthopedic management, and mobility support. Accurate coding captures the chronic rehabilitative care needs.
Documentation Requirements
- ✓Diagnosis of cerebral palsy with spastic diplegic type specified
- ✓Predominant involvement of lower extremities documented
- ✓Birth history: prematurity, periventricular leukomalacia when applicable
- ✓Ambulatory status: independent, assisted, wheelchair-dependent
- ✓Associated conditions: learning disabilities, strabismus, urinary issues
- ✓Current interventions: physical therapy, orthopedic procedures, assistive devices
Commonly Confused Codes
- •G80.0: Spastic quadriplegic cerebral palsy involves all four limbs severely; diplegia primarily affects legs
- •G80.2: Spastic hemiplegic cerebral palsy affects one side only, not bilateral lower extremities
- •G82.20: Paraplegia, unspecified is for acquired spinal cord-level paralysis, not cerebral palsy
- •G80.9: Cerebral palsy, unspecified should not be used when the diplegic pattern is documented