HCPCS Code J0364: Apomorphine hydrochloride billing guide

Key takeaways

HCPCS Code J0364 describes injection of apomorphine hydrochloride, 1 mg, a dopamine agonist sold as Apokyn for Parkinson’s off episodes.

Bill one unit per 1 mg administered, so a typical 2 mg dose requires 2 units on the claim.

Medicare Part B covers J0364 only when a clinician administers it in-office. Patient self-injection does not qualify under Part B.

Every Part B claim line needs modifier JW or JZ, plus the 11-digit NDC from the vial administered.

Practice management software like Pabau links the administered dose to the claim, so unit counts and modifiers match the note.

HCPCS Code J0364 is the billing code for injection of apomorphine hydrochloride, 1 mg. It covers Apokyn, the rescue injection used for sudden off episodes in advanced Parkinson’s disease. One unit equals 1 mg administered, so a 2 mg dose bills as 2 units.

This reference covers the official descriptor, Medicare Part B coverage, the unit math, required modifiers, ICD-10 pairing, and the buy-and-bill process. Denials usually trace back to the unit count, a missing JW or JZ modifier, or an expired prior authorization.

HCPCS Code J0364: Official descriptor and code details

HCPCS Code J0364 is a permanent Level II code maintained by CMS that covers the injection of apomorphine hydrochloride at one milligram per billing unit. The code has been active since 2006 and is classified under the J-code section for drugs administered by routes other than oral.

Practices that administer apomorphine should record the dose in milligrams in the clinical note. Translate that figure into billing units before submitting, because a mismatch between the note and the claim triggers automated edits.

Claims management software that links the clinical note to the claim line keeps those numbers in step.

Clinical background: Apomorphine hydrochloride and Parkinson’s disease

Apomorphine hydrochloride is a non-ergot dopamine agonist with rapid onset, typically working within 10 to 20 minutes of subcutaneous injection. The FDA approved Apokyn specifically for acute, intermittent treatment of hypomobility “off” episodes in patients with advanced Parkinson’s disease.

An “off” episode occurs when levodopa wears off prematurely, leaving patients with sudden freezing, rigidity, or inability to move. Because apomorphine causes severe nausea, patients need antiemetic pretreatment before the first injection and ongoing antiemetic coverage during titration.

This matters for billing. The antiemetic and the titration visit may each carry their own codes alongside J0364. Practices that run apomorphine titration need structured records for every dose. Clinical notes software that captures the dose, the route, and the antiemetic keeps that detail with the claim.

Only subcutaneous injection is FDA-approved for apomorphine hydrochloride. Sublingual apomorphine film, sold as Kynmobi, uses a separate code and should never be billed under J0364.

Medicare coverage and reimbursement for J0364

Medicare Part B covers J0364 when a qualified healthcare professional administers apomorphine in a clinical setting. Coverage follows incident-to billing rules. The supervising physician must be present in the office suite during administration.

Patient self-injection does not qualify for Part B coverage under J0364. The self-administered drug exclusion section below covers the detail.

J0364 fee schedule rates

CMS reimburses separately payable Part B drugs at the Average Sales Price (ASP) plus 6% under the Physician Fee Schedule. Because ASP rates update quarterly, verify the current J0364 payment amount in the CMS ASP drug pricing file before submitting claims.

The table below shows the rate structure. Confirm the payment figures against the current quarter’s CMS release.

For commercial payers, reimbursement rates and coverage criteria vary. Some plans apply specialty tier pricing or require step therapy before approving apomorphine. Always confirm the patient’s plan benefits before the first administration.

Structured medical documentation that captures payer-specific authorization numbers alongside the clinical note prevents delays at adjudication.

How to bill HCPCS Code J0364: Units and dosage

J0364 is billed per 1 mg of apomorphine hydrochloride administered. A 2 mg titration dose bills as 2 units. A 4 mg maintenance dose bills as 4 units. Never round down to a single unit when more than 1 mg was given.

• Calculate units from the administered dose: units billed = total mg administered (e.g., 3 mg = 3 units)
• Use the exact vial concentration: Apokyn is supplied as 10 mg/mL, so document mL drawn and mg administered separately
• Bill only what was administered: wastage from single-use vials is handled through modifier JW or JZ (see the modifier section)
• Match the claim units to the clinical note: discrepancies trigger automated edits and manual review
• Do not combine units from separate episodes on one claim line without confirming your MAC’s policy on same-day administration

The National Drug Code (NDC) must also appear on the claim for all Part B separately payable drugs. Include the 11-digit NDC, the unit qualifier (UN for units), and the quantity in NDC units on the claim. A missing NDC is a routine medical billing error that sends J-code claims back for correction.

Required modifiers when billing J0364

Modifier selection directly affects whether CMS pays or recaptures the claim. Apply the correct modifier for every J0364 claim line.

Under the CMS JW/JZ modifier final rule, one of JW or JZ must appear on every Medicare Part B drug claim line. Failing to include either modifier results in a claims edit that will suspend the claim. Verify how these modifiers apply to apomorphine vial sizes with your Medicare Administrative Contractor (MAC) before billing.

ICD-10 diagnosis codes used with J0364

CMS requires a medically necessary ICD-10-CM diagnosis code on every J0364 claim. Parkinson’s disease codes were expanded into subcategories in FY2024.

Billing the legacy G20 without a subcategory may trigger a reject from some MACs. Verify current valid codes against the CMS ICD-10 codes page each fiscal year.

The clinical note should specify the patient’s Parkinson’s stage, the nature and frequency of off episodes, and why apomorphine was selected over other rescue therapies. This documentation links the diagnosis code to medical necessity in a way that survives audit.

HIPAA-compliant documentation rules also apply here. Apomorphine records must be retained under state and federal record-keeping requirements.

Buy-and-bill process for J0364 (Apokyn)

The buy-and-bill model lets a practice purchase Apokyn directly, administer it in-office, and then bill Medicare Part B for the drug at ASP+6%. Neurology and movement disorder practices use it most, though primary care practices that co-manage Parkinson’s patients face the same claim mechanics.

1. Acquire the drug: Purchase Apokyn from a wholesale distributor or specialty pharmacy. Document the NDC, lot number, and acquisition cost in your inventory records.
2. Verify coverage before administration: Confirm Part B eligibility first. For commercial patients, check authorization status in prescription management software that stores approval numbers on the patient record.
3. Administer and document: Record the dose in mg, the route, the injection site, the time, and the patient’s response.
4. Submit the claim: Bill J0364 with the unit count matching mg administered. Add the NDC with its qualifier and quantity, the JW or JZ modifier, and the ICD-10-CM code.
5. Reconcile reimbursement: Compare the Medicare remittance to the acquisition cost. The 6% margin above ASP covers acquisition and handling, so track drug costs as part of revenue cycle management.

Practices that administer several injectable drugs under buy-and-bill benefit from automated billing workflows. The right code, modifier, and NDC attach at the point of administration instead of at billing time.

Prior authorization requirements for J0364

Medicare Part B does not require prior authorization for J0364 at the national level, but individual Medicare Advantage plans and commercial payers often do. Requirements for apomorphine vary by plan year, so billing staff should verify each patient’s plan before scheduling an administration appointment.

• Medicare fee-for-service: No national prior auth requirement. Coverage is decided on medical necessity at the claim level
• Medicare Advantage: Plans vary, and some require prior auth for specialty injectables including apomorphine
• Commercial and employer plans: Step therapy is common. Insurers may require documented failure of oral dopamine agonists first
• Medicaid: Requirements differ by state. Many state programs require prior auth for J-code injectables above a cost threshold

Keep a copy of every prior authorization approval in the patient record alongside the clinical note for each administration. Digital forms let practices store and retrieve approval numbers at the time of billing, without searching paper files. Record the authorization number on the claim in the appropriate field to prevent retrospective denial.

Self-administered drug exclusion and J0364

CMS excludes most self-administered drugs from Medicare Part B coverage under the self-administered drug (SAD) exclusion. Apomorphine appears on the CMS exclusion list, but the exclusion does not apply when a qualified healthcare professional administers the drug in a clinical setting.

Who administered the dose decides coverage. If the patient self-injects at home, Part B does not pay for the drug. If a clinician administers it in-office, J0364 is billable.

• In-office administration by a clinician: J0364 billable under Part B
• Patient self-injection at home: Not covered by Part B; may be covered by Part D
• Titration visits in the office: Billable under Part B when the clinician administers the dose
• Take-home supply after titration: Part D coverage territory; do not bill J0364 for take-home supply

Document who administered each dose. “Administered by [clinician name and credential]” should appear explicitly in the clinical note alongside the date and time. Vague documentation that leaves the administrator ambiguous is the primary trigger for SAD exclusion denials on audit.

Patient data security tools that log the administering clinician as part of the electronic record give you an audit-ready trail without extra documentation steps.

Related HCPCS and CPT codes

J0364 rarely appears on a claim in isolation. The administration service, antiemetic pretreatment, and any evaluation and management visit typically generate additional claim lines. Use the AAPC HCPCS code lookup to verify current descriptor language for each related code before billing.

When billing 96372 alongside J0364, add modifier 25 to any same-day E/M code to show the evaluation was separate.

Verify this requirement with your MAC, since some carriers have specific policies for neurology injection visits. Practice management software with code bundling rules stops these edits before the claim reaches the payer.

How Pabau keeps J-code claims and clinical notes in step

In a typical practice, the J0364 claim gets built twice. A clinician records the dose in the chart, then a biller retypes the units, the NDC, and the modifier into the claim. Every retype is a chance for the two records to drift apart.

Practice management software like Pabau keeps one record for both jobs. The administered dose, the route, the authorization number, and the administering clinician all sit in the note that supports the claim. Billing staff work from that record instead of chasing paper.

The same workflow applies wherever a practice documents and bills what it administers, including the physical therapy practices that co-manage Parkinson’s patients. Every Pabau subscription includes the full claims, documentation, and reporting toolset, so nothing here sits behind a higher tier.

Manage J-code billing without the manual rework

Pabau links clinical documentation to billing claims, so unit counts, modifiers, and NDC details travel from the note to the claim automatically.

Book a demo

Conclusion

The billing decisions on J0364 are small and unforgiving. Bill one unit per milligram, attest with JW or JZ on every line, and name the administering clinician in the note. A practice that gets those three right rarely sees this code come back.

The trade-off worth remembering is where the work happens. Capturing the dose, the route, and the authorization at the moment of administration costs seconds. Reconstructing them weeks later, after a denial, costs far more. Book a demo to see how Pabau keeps J-code documentation and claims in one record.

Continue your research

Need a prior authorization form your billing team can reuse? Medical prior authorization form gives you a fillable template for specialty drug approvals.

Unsure which NPI belongs on the claim? Type 1 vs type 2 NPI explains how individual and organizational identifiers differ on a claim.

Billing another Part B injectable this week? J2597 walks through units, coverage, and documentation for a second J-code.

Coding parkinsonism outside the ICD-10 system? 8A00 covers the ICD-11 classification and how it appears in clinical records.

Standardizing how clinicians write up each visit? Medical notes template gives your team a consistent structure for documenting treatment.

Frequently asked questions