What Does ICD-10 Code G80.0 Mean?
ICD-10-CM code G80.0 designates a diagnosis of spastic quadriplegic cerebral palsy — a nonprogressive neurological disorder originating from brain damage sustained during the prenatal, perinatal, or early postnatal period, resulting in increased muscle tone (spasticity) that affects all four limbs and, typically, the trunk. It is the most severe subtype within the spastic cerebral palsy category and carries significant functional implications for affected individuals.
Key attributes of this code:
- Billable/valid code: Yes — valid for claims with dates of service from October 1, 2025 through September 30, 2026 (FY2026)
- Applicable setting: Inpatient and outpatient (default “yes” for both principal and first-listed diagnosis)
- HCC-mapped: Yes — G80.0 maps to CMS-HCC Risk Adjustment Model hierarchical condition categories relevant to Medicare Advantage plans
- Synonyms recognized: Congenital spastic paralysis (cerebral); quadriplegic spastic cerebral palsy; tetraplegia due to cerebral palsy
What Conditions and Diagnoses Does G80.0 Cover?
G80.0 is used when the medical record documents spastic cerebral palsy with involvement of all four extremities. It is not a catch-all for any type of motor dysfunction — the spastic subtype and quadriplegic distribution must both be explicitly established.
Clinical presentations and scenarios appropriately captured by this code include:
- Spastic motor disorder in all four limbs with documented cerebral etiology
- Congenital spastic paralysis of cerebral origin affecting both upper and lower extremities
- Periventricular leukomalacia (PVL) or hypoxic-ischemic encephalopathy (HIE) sequelae resulting in quadriplegic spastic CP
- Ongoing management of established spastic quadriplegic CP, regardless of patient age (pediatric or adult)
What Does G80.0 Specifically Exclude?
The ICD-10-CM tabular includes an Excludes1 note at the G80 category level. Coders must not assign G80.0 when documentation supports:
- Hereditary spastic paraplegia (G11.4) — a genetically driven condition distinct from cerebral palsy; cannot be coded simultaneously with G80.0
- Acquired spastic quadriplegia due to traumatic spinal cord injury (coded from the S category with sequela 7th character)
- Acquired quadriplegia from stroke or other cerebrovascular event (G81–G82 range with underlying cause)
When Is G80.0 the Right Code to Use?
Selecting G80.0 over other cerebral palsy or paralysis codes requires deliberate verification against the clinical record. Follow this criteria sequence before assigning:
- Confirm cerebral etiology — The quadriplegia must originate from a brain-based, nonprogressive disorder, not a spinal cord lesion or progressive neurological disease.
- Confirm spastic subtype — Documentation must reflect increased muscle tone/spasticity (e.g., Modified Ashworth Scale scores, clonus, hyperreflexia), not athetoid, ataxic, or mixed movement patterns.
- Confirm quadriplegic distribution — All four limbs must be involved. If spasticity is limited to the lower extremities, evaluate G80.1 (diplegic) instead.
- Confirm congenital/early-onset origin — The brain injury must predate meaningful neurological development (prenatal through first several years of life).
- Confirm no Excludes1 conflict — Rule out hereditary spastic paraplegia (G11.4) before assigning G80.0.
How Does G80.0 Differ From the Most Commonly Confused Codes?
| Code | Condition | Key Distinction From G80.0 |
|---|---|---|
| G80.1 | Spastic diplegic CP | Spasticity predominantly affects lower limbs; upper extremity involvement is minimal or absent |
| G80.2 | Spastic hemiplegic CP | Spasticity affects only one side of the body (arm + leg unilateral) |
| G80.9 | Cerebral palsy, unspecified | No subtype or distribution documented; last resort when CP is confirmed but specifics are absent |
| G82.50 | Quadriplegia, unspecified | Acquired quadriparesis/plegia — NOT cerebral palsy; used when no CP etiology is established |
| G11.4 | Hereditary spastic paraplegia | Genetically inherited progressive disorder; Excludes1 from G80 category — cannot be coded with G80.0 |
What Documentation Is Required to Support G80.0?
Inadequate documentation is the leading driver of claim denials and audit findings for this code. The provider’s record must do more than list a diagnosis — it must substantiate the subtype and distribution.
What Must the Provider Document in the Clinical Notes?
A compliant encounter note should include all of the following:
- Explicit diagnosis statement — “Spastic quadriplegic cerebral palsy” written verbatim, or a clear equivalent such as “congenital spastic paralysis affecting all four limbs.”
- Etiology or onset history — Documentation of the causative brain injury event (e.g., prematurity at 28 weeks, periventricular leukomalacia, perinatal HIE, intrauterine infection).
- Limb involvement assessment — A functional or neurological examination documenting motor findings in both upper and lower extremities bilaterally.
- Spasticity quantification — Modified Ashworth Scale or similar scoring applied to affected limbs (e.g., “UE 3/4, LE 2/4 on MAS”).
- Associated conditions addressed — Intellectual disability, epilepsy, dysarthria, dysphagia, and visual impairment are common comorbidities requiring separate coding when documented and managed.
- Treatment plan relevance — Documentation that the diagnosis is actively influencing clinical management (physical therapy, antispasmodic medications, orthotics, baclofen pump management).
Which Diagnostic or Lab Results Support This Code?
Unlike many diagnoses, G80.0 does not require laboratory confirmation — it is a clinical diagnosis. However, the following findings significantly strengthen medical necessity documentation and audit defensibility:
- Brain MRI or CT findings consistent with periventricular leukomalacia, cortical atrophy, or hypoxic-ischemic injury patterns
- Neurological evaluation reports from a neurologist or developmental pediatrician confirming the diagnosis
- Physical/occupational therapy assessments documenting spasticity severity and functional limitations in all four extremities
- Genetic testing results — not required but may be documented to rule out hereditary conditions (supporting the exclusion of G11.4)
What Is the Documentation Standard for Inpatient vs. Outpatient Settings?
| Setting | Standard | Key Distinction |
|---|---|---|
| Outpatient | First-listed diagnosis — code the condition that is the primary reason for the visit | G80.0 may be secondary when the visit is for a comorbidity (e.g., seizure management) |
| Inpatient | Principal diagnosis — the condition determined after study to be chiefly responsible for admission | G80.0 can be principal when admission is for spasticity management, baclofen pump implantation, or functional decline |
| HCC Risk Adjustment | Annual documentation required — CP must be documented at least once per measurement year to recapture the HCC value | Failure to re-document results in lost RAF score value; critical for Medicare Advantage plans |
In practice, coders frequently encounter adult patients (ages 30–60+) with G80.0 whose primary care notes reference a childhood CP diagnosis without re-documenting specifics. Auditors flag this as insufficient — the treating provider must re-establish the diagnosis annually, not merely reference prior records.
How Does G80.0 Affect Medical Billing and Claims?
G80.0 carries meaningful reimbursement implications beyond simple claim submission. Coders and billers should be aware of these payer-level considerations:
- MS-DRG grouping: G80.0 maps to MS-DRG v43.0 groups within the nervous system disease category, influencing inpatient facility reimbursement weights.
- Medicare Advantage risk adjustment: G80.0 maps to an HCC category, meaning accurate and annual coding directly affects the plan’s risk-adjusted premium revenue and the practice’s quality metrics.
- Medical necessity triggers: Payers require documentation of functional limitation or active treatment when G80.0 appears as the primary diagnosis on therapy claims (PT, OT, SLP).
- DME coverage: G80.0 is a recognized supporting diagnosis for power wheelchair and specialized seating claims under CMS DME MAC LCD policies. The diagnosis alone does not guarantee coverage — functional assessment and face-to-face examination documentation are also required.
What CPT or Procedure Codes Are Commonly Billed With G80.0?
| CPT Code | Description | Typical Pairing Context |
|---|---|---|
| 97110 | Therapeutic exercises | PT/OT visits for tone management and motor function |
| 97530 | Therapeutic activities | Functional training in ADLs for quadriplegic CP patients |
| 64644 / 64645 | Chemodenervation (Botox injection) — trunk/extremity muscles | Spasticity management via intramuscular Botox |
| 62362 | Implantation of intrathecal drug infusion pump | Baclofen pump placement for severe spasticity |
| 62367–62370 | Electronic analysis / reprogramming of pump | Ongoing baclofen pump management visits |
| 99213–99215 | Office/outpatient E&M | Routine neurology or developmental pediatrics follow-up |
Are There Any Prior Authorization or Coverage Restrictions?
- Botox injections (chemodenervation): Most commercial payers and Medicaid require prior authorization; documentation must specify the targeted muscles, dosage, and functional goal.
- Baclofen pump implantation: Requires pre-authorization with documented failure of conservative spasticity management (oral agents, therapy).
- Power wheelchairs (DME): Requires a face-to-face examination, written order, and detailed product request from a treating physician — G80.0 supports but does not independently establish coverage.
- Therapy services: Medicare and many commercial plans require documented functional goals and measurable progress to continue coverage; maintenance-only therapy for stable CP patients may be denied under skilled-care criteria.
What Coding Errors Should You Avoid With G80.0?
The following errors appear most frequently in coding audits and claim denials involving G80.0:
- Coding G80.0 for acquired quadriplegia — Assigning this code when the patient has quadriplegia from a stroke, spinal cord injury, or progressive neurological disease; the correct codes are in the G81–G82 or injury ranges.
- Upcoding to G80.0 from vague documentation — Using G80.0 when the record says only “cerebral palsy” or “spastic CP” without specifying the quadriplegic distribution; use G80.9 unless the provider explicitly documents all-limb involvement.
- Omitting comorbidity codes — Failing to additionally code epilepsy (G40.–), intellectual disabilities (F70–F79), dysphagia (R13.10), or visual impairment (H54.–) when the provider documents and manages these conditions.
- Ignoring the Excludes1 note — Assigning G80.0 alongside G11.4 (hereditary spastic paraplegia), which is a hard exclusion.
- Not coding G80.0 annually in risk-adjusted populations — Allowing the HCC to lapse in Medicare Advantage patients by omitting the diagnosis from annual wellness or chronic care management visits.
What Do Auditors Look for When Reviewing Claims With G80.0?
- Mismatch between the ICD-10 code and the provider’s documented diagnosis (e.g., record says “diplegia,” claim says G80.0)
- Absence of neurological or functional assessment supporting all-four-limb involvement
- Missing etiology documentation for new or recently assumed diagnoses
- Botox or baclofen pump claims without supporting spasticity severity documentation
- DME claims with G80.0 that lack a compliant face-to-face examination note
How Does G80.0 Relate to Other ICD-10 Codes?
Understanding the broader G80 category and adjacent paralysis codes is essential for accurate diagnosis code specificity and proper sequencing.
| Code | Condition | Relationship to G80.0 | Key Distinction |
|---|---|---|---|
| G80 | Cerebral palsy (category) | Parent category | Not billable — must select a specific subcategory |
| G80.1 | Spastic diplegic CP | Same category, different distribution | Lower limbs predominantly affected |
| G80.2 | Spastic hemiplegic CP | Same category, different distribution | Unilateral (one side) involvement |
| G80.3 | Athetoid CP | Same category, different movement type | Involuntary/writhing movements, not spasticity |
| G80.9 | CP, unspecified | Fallback — less specific | No subtype documented; use only when specificity unavailable |
| G11.4 | Hereditary spastic paraplegia | Excludes1 — cannot co-exist | Genetic/progressive; not a cerebral palsy subtype |
| G82.50 | Quadriplegia, unspecified | Acquired vs. congenital | Used for non-CP quadriplegia (e.g., SCI, stroke sequelae) |
| F70–F79 | Intellectual disabilities | Common comorbidity — use additional code | Separately coded when documented and managed |
| G40.– | Epilepsy | Common comorbidity — use additional code | Seizure disorders occur in a significant proportion of spastic quadriplegic CP patients |
What Is the Correct Code Sequencing When G80.0 Appears With Other Diagnoses?
- Outpatient: List G80.0 first only when it is the primary reason for the encounter. If the visit is for seizure management in a patient with known G80.0, sequence the epilepsy code first and G80.0 as a secondary diagnosis.
- Inpatient: Apply Uniform Hospital Discharge Data Set (UHDDS) principal diagnosis rules — the condition most responsible for admission after study is listed first.
- Comorbidities: Epilepsy, intellectual disability, dysphagia, and visual impairment are sequenced after G80.0 when G80.0 is principal, or after the primary visit reason when G80.0 is secondary.
- No “code first” or “use additional code” instruction applies to G80.0 itself — sequencing is driven purely by clinical context and setting-specific guidelines.
Real-World Coding Scenario — How G80.0 Is Applied in Practice
Encounter summary: A 19-year-old male with a history of spastic quadriplegic cerebral palsy secondary to periventricular leukomalacia (confirmed on neonatal MRI) presents to a neurology outpatient clinic for routine management. The neurologist documents spasticity in all four extremities (Modified Ashworth Scale 3 in upper extremities, 2 in lower extremities), active epilepsy managed with levetiracetam, and mild intellectual disability. The visit purpose is spasticity monitoring and medication management.
Correct Code Application
- G80.0 — Spastic quadriplegic cerebral palsy (primary reason for visit — spasticity management)
- G40.909 — Epilepsy, unspecified, not intractable, without status epilepticus (documented and managed)
- F70 — Mild intellectual disability (documented comorbidity)
Rationale: The provider explicitly documented the subtype and limb distribution, named the etiology (PVL), and quantified spasticity — all required elements. Comorbidities are separately coded per ICD-10-CM Official Coding Guidelines Section I.C.
Common Mistake in This Scenario
- Incorrect code selected: G80.9 (Cerebral palsy, unspecified)
- Why it fails: The provider clearly documented “spastic quadriplegic” — using the unspecified code misrepresents clinical specificity, undermines HCC risk adjustment accuracy, and may trigger a coding query. Auditors flag this pattern as a failure to capture available specificity, which can affect both reimbursement and quality reporting.
Frequently Asked Questions About ICD-10 Code G80.0
Is ICD-10 Code G80.0 Valid for Use in 2026?
ICD-10-CM code G80.0 is a valid, billable diagnosis code for fiscal year 2026, covering claims with dates of service from October 1, 2025 through September 30, 2026. No changes to its description, validity status, or inclusion notes have been applied in the FY2026 release. Coders should verify annually against the ICD-10-CM Official Coding Guidelines published by CMS at cms.gov.
What Is the Difference Between G80.0 and G80.9?
G80.0 requires that the provider specifically document spastic cerebral palsy affecting all four limbs, whereas G80.9 is used only when cerebral palsy is confirmed but the subtype or distribution cannot be determined from available documentation. Using G80.9 when G80.0 is clearly supported constitutes a lack of diagnosis code specificity and can negatively affect risk-adjusted reimbursement in Medicare Advantage populations.
Can G80.0 Be Used for Adult Patients, or Is It Only for Children?
G80.0 applies to patients of any age — cerebral palsy is a lifelong condition and does not resolve. Adult patients with established spastic quadriplegic CP require ongoing annual documentation of the diagnosis by the treating provider, particularly in Medicare Advantage risk-adjustment contexts, to ensure the HCC value is captured each measurement year.
Does G80.0 Cover Spastic Quadriplegia Caused by a Traumatic Brain Injury?
G80.0 is not appropriate for spastic quadriplegia that results from a traumatic brain injury (TBI) sustained after the early developmental period. Acquired spasticity following TBI is coded using the injury category (S06.–) with a sequela seventh character, potentially alongside G82.– for functional paralysis. The cerebral palsy category (G80) is reserved for nonprogressive brain damage originating in the perinatal or early developmental period.
What CPT Codes Are Most Commonly Billed With G80.0?
The most frequent procedure code pairings with G80.0 include therapeutic exercise (97110), therapeutic activities (97530), chemodenervation for spasticity (64644/64645 for Botox injections), and baclofen pump implantation (62362) or reprogramming (62367–62370). Power wheelchair justification documentation commonly cites G80.0 as a supporting diagnosis under applicable CMS DME MAC LCD policies.
What Are the Most Common Documentation Errors That Lead to Claim Denials for G80.0?
The most frequent denial triggers for G80.0 claims are: (1) vague documentation that says only “cerebral palsy” without specifying quadriplegic distribution, leading to downcoding to G80.9; (2) missing etiology documentation in adult patients where the childhood diagnosis is assumed rather than re-established; and (3) absence of functional assessment findings to support medical necessity on therapy or DME claims.
Key Takeaways
Every coder working with G80.0 should keep the following principles in practice:
- G80.0 is the most severe spastic cerebral palsy subtype — all four limbs must be documented as affected; do not assign when only lower extremity spasticity is described.
- The Excludes1 note at the G80 category level prohibits simultaneous use of G80.0 and G11.4 (hereditary spastic paraplegia).
- G80.0 carries HCC risk-adjustment value — annual re-documentation by the treating provider is required for Medicare Advantage capture.
- Comorbidities must be coded separately — epilepsy, intellectual disability, dysphagia, and visual impairment require their own codes when documented and managed.
- Provider language matters — the record must say “spastic quadriplegic” or equivalent; vague CP documentation should prompt a coding query before assigning G80.0.
- G80.0 supports but does not independently authorize DME, Botox, or baclofen pump coverage — functional documentation and prior authorization requirements apply.
- For coding audit preparation, ensure every G80.0 claim is backed by a neurological or functional assessment documenting spasticity in all four extremities.
For authoritative code guidance, refer to the ICD-10-CM Official Coding Guidelines published annually by CMS at cms.gov/medicare/coding-billing/icd-10-codes, and consult AHA Coding Clinic advisories for condition-specific direction on cerebral palsy coding nuances.
Content is intended for educational purposes only. Always verify code validity and payer-specific requirements against the current ICD-10-CM code set and applicable Local Coverage Determinations (LCDs).