G9033 Amantadine Oral 100mg HCPCS Reimbursement | OpenPayer

Summary & Overview

HCPCS G9033: Amantadine Hydrochloride Oral, 100 mg

HCPCS Level II code G9033 identifies a branded oral formulation of amantadine hydrochloride billed per 100 mg unit for use within Medicare-approved demonstration projects. This code is relevant nationally because it standardizes billing for a specific medication formulation tied to demonstration initiatives, affecting how pharmacies and participating providers capture costs and report utilization in limited program settings. Medicare is the primary public payer associated with this code due to the demonstration project context; commercial carriers commonly involved in national analyses include Aetna, Blue Cross Blue Shield, Cigna Health, and UnitedHealthcare.

Readers will find a concise overview of the code’s clinical context, the typical service setting (pharmacy-dispensed oral medication), and which payers are relevant in national discussions. The publication summarizes benchmarks where available, explains the code’s role in demonstration project billing, and highlights policy or coverage considerations that influence use in practice. Data elements not provided in the input are noted as unavailable; the report avoids clinical or prescribing guidance and focuses on billing, coding, and program context for G9033.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG9033HCPCS Level IIamantadineoral medicationpharmacy billingMedicare demonstrationdrug codingmedication unit pricingoutpatient pharmacy

Billing Code Overview

HCPCS Level II code G9033 represents Amantadine hydrochloride, oral brand, per 100 mg (for use in a Medicare-approved demonstration project). The code denotes a branded oral antiviral/antiparkinsonian medication formulation measured per 100 mg unit for distribution within the scope of a Medicare demonstration project.

Service Type: Pharmacy-dispensed oral medication

Typical Site of Service: Outpatient pharmacy or facility pharmacy for patients enrolled in a Medicare-approved demonstration project

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A Medicare beneficiary enrolled in a CMS-approved demonstration project receives an oral formulation of amantadine hydrochloride, brand-name, supplied as 100 mg tablets. Typical patient is an older adult with Parkinsonian signs or drug-induced extrapyramidal symptoms requiring symptomatic management. The workflow begins with a neurologist or geriatrician documenting the indication, prior therapies, and informed consent for participation in the demonstration. A prescription is written specifying the brand oral amantadine 100 mg; the pharmacy dispenses the product under the demonstration project billing rules and submits claim using G9033. Nursing documents medication counseling, adherence checks, and monitoring for common adverse effects (confusion, hallucinations, orthostatic hypotension, peripheral edema, livedo reticularis). Follow-up visits include medication effectiveness assessment, review of potential interactions (anticholinergics, sympathomimetics), and renal function monitoring to guide dose adjustments. Typical site of service is outpatient clinic or outpatient pharmacy dispensing within a Medicare demonstration project setting.

Coding Specifications

Modifier	Description	When to Use
`LT`	Left side	Use when laterality is relevant and required by payer documentation (rare for oral drugs).

Related Codes

HCPCS-G8974-HEMOGLOBIN-NOT-DOCUMENTED

HCPCS G8974: Hemoglobin Level Measurement Not Documented

HCPCS-G2119-CALCIUM-VITAMIN-D-OPTIMIZATION

HCPCS G2119: Calcium and/or Vitamin D Optimization

HCPCS-G0682-HUMAN-CELL-TISSUE-SKIN-SUBSTITUTE-APPLICATION

HCPCS G0682: Application of Non-Sheet Human Cell/Tissue Skin Substitute

HCPCS-G2115-FRAILTY-WITH-DEMENTIA-MEDICATION-DISPENSED-66-80

HCPCS G2115: Frailty with Dispensed Dementia Medication, Ages 66–80

HCPCS-G9698-NO-LONG-ACTING-INHALED-BRONCHODILATOR-DOCUMENTED-REASON

HCPCS G9698: Documentation of Reason for Not Prescribing Long-Acting Inhaled Bronchodilator

HCPCS-G6035-GOLD-PRECIOUS-METAL-PRODUCT

HCPCS G6035: Gold Product for Clinical Use

HCPCS-G9316-RISK-ASSESSMENT-PATIENT-COMMUNICATION

HCPCS G9316: Patient-Specific Risk Assessment and Communication

HCPCS-G9842-METASTATIC-DISEASE-AT-DIAGNOSIS

HCPCS G9842: Metastatic Disease at Diagnosis

HCPCS-G8866-PNEUMOCOCCAL-VACCINE-DOCUMENTATION-REFUSAL

HCPCS G8866: Documentation of Reason for Not Receiving Pneumococcal Vaccine

HCPCS-G9466-AOE-MEASURES-QUALITY-ACTION-COMPLETION

HCPCS G9466: Completion of AOE Measures Quality Actions

Showing 1–10 of 1996

Taxonomy Code	Specialty	Notes
`207R00000X`	Neurology	Neurologists commonly prescribe amantadine for Parkinson disease and levodopa-induced dyskinesia.
`207RH0000X`	Neurology - Adult	Adult neurologists manage movement disorder therapy including amantadine.
`207L00000X`	Geriatric Medicine	Geriatricians prescribe and monitor amantadine in older adults with parkinsonism or drug-induced movement disorders.
`163W00000X`	Pharmacy	Pharmacists dispense branded oral amantadine and manage formulary/demonstration documentation.
`207T00000X`	Physical Medicine & Rehabilitation	PM&R specialists may co-manage patients with movement disorders who receive symptomatic pharmacotherapy.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G20`	Parkinson disease	Primary indication for symptomatic use of amantadine in some patients to reduce motor symptoms and dyskinesia.
`G21.1`	Secondary Parkinsonism due to antipsychotics	Amantadine can be used off-label for drug-induced parkinsonism or extrapyramidal symptoms.
`G25.1`	Drug-induced tremor	Amantadine may be considered as part of symptomatic management for medication-related movement disorders.
`G24.02`	Drug-induced dystonia, acute or tardive	Amantadine is sometimes used adjunctively for specific extrapyramidal movement disorders.
`R29.3`	Abnormal posture	Used when symptomatic movement disorder features such as postural abnormalities are being treated with amantadine.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`99213`	Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes	Common visit code for follow-up assessment of symptom response, side effects, and medication management after initiating amantadine.
`99214`	Office or other outpatient visit for the evaluation and management of an established patient, typically 25 minutes	Used for more complex medication management visits involving detailed medication review and coordination of care for patients on amantadine.
`36415`	Collection of venous blood by venipuncture	Often performed to obtain basic metabolic panel or renal function tests to monitor dosing and safety of amantadine.
`99406`	Smoking and tobacco use cessation counseling visit, intermediate, greater than 3 minutes up to 10 minutes	May be used when counseling addresses medication interactions or behavioral management as part of care plan (used when applicable).
`99070`	Supplies and materials (unless otherwise specified)	May be billed for durable/non-covered items or documentation supplies associated with participation in a demonstration project, per payer policy.