JZ Modifier — Zero Drug Amount Discarded
Last reviewed: May 2, 2026 by Catherine Rose, CPC · Source: CMS Internet-Only Manual Publication 100-04, Chapter 17, §40
Quick Answer
What is the JZ modifier and when does it apply?
JZ is a HCPCS Level II modifier that means “zero drug amount discarded.” You append it to a Medicare Part B drug claim when the drug came from a single-dose container and none was wasted. Required on every applicable claim line; CMS began returning claims as unprocessable when missing in 2024.
Use JZ when nothing was discarded. Use JW when there was discarded drug. Never both on the same claim line. Multi-dose vials are exempt — the modifiers apply only to single-dose containers.
Most common case: adult flat-dose drugs where the dose lines up with whole vial counts (Ocrevus 600 mg = 2× 300 mg vials, Briumvi 450 mg = 1.5× 300 mg vials — only with the new vial size, Keytruda 200 mg = 1× 200 mg vial). Zero waste → JZ on the line.
When JZ applies vs. when it doesn’t
Apply JZ when…
- Drug is dispensed from a single-dose container (single-dose vial, prefilled syringe, ampule, single-dose auto-injector).
- Zero milligrams (or zero billable units) were discarded — the entire vial content was administered.
- Drug is billed under Medicare Part B (or a payer that follows Medicare Part B claim-edit rules).
- Patient is on Medicare Part B, Medicare Advantage that has adopted the JZ rule, or a commercial payer with the requirement in contract.
- Adult flat-dose drugs that line up with whole vial counts (the typical case).
Do not apply JZ when…
- Drug came from a multi-dose vial. JZ and JW apply only to single-dose containers.
- Any drug was discarded. Use JW on the wasted units instead.
- You’re billing the administration code (e.g., 96413, 96365). JZ goes on the drug line, not the administration line.
- Drug is billed under Part D (oral specialty drugs, self-administered injectables on the pharmacy benefit).
- Drug is on the Medicare Self-Administered Drug (SAD) exclusion list.
30-second decision tree
- Is the drug from a single-dose container? If no → no JZ, no JW (multi-dose vials are exempt).
- Was any drug discarded after dosing the patient?
- No drug discarded → JZ on the drug line.
- Some drug discarded → the administered units use nothing (or are billed on a separate line that needs no waste-modifier), and the discarded units are billed on a separate line with JW.
- Is the payer Medicare Part B or a payer that follows Part B edits? If yes, the modifier is required and the claim will reject without it.
Worked examples (real J-codes from our drug library)
Ocrevus maintenance
J2350 / ocrelizumab / 1 mg = 1 unit
Apply JZ
- Vial size
- 300 mg single-dose vial (NDC 50242-150-01)
- Dose
- 600 mg q24wk maintenance
- Vials used
- 2× 300 mg = 600 mg total drawn up
- Administered
- 600 mg
- Discarded
- 0 mg
- Billing units
- 600 (J2350 = 1 unit per mg)
JZ on the J2350 line. Both vials fully administered with no waste. The full Ocrevus reference page is at
/drugs/ocrevus.
Keytruda flat-dose
J9271 / pembrolizumab / 1 mg = 1 unit
Apply JZ
- Vial size
- 100 mg/4 mL single-dose vial
- Dose
- 200 mg q3wk
- Vials used
- 2× 100 mg vials
- Administered
- 200 mg
- Discarded
- 0 mg
- Billing units
- 200
JZ on the J9271 line. Whole-vial dosing — the most common scenario for adult flat-dose oncology drugs.
Pediatric weight-based dose
J9271 / pembrolizumab / pediatric 2 mg/kg
Apply JW (separate line)
- Vial size
- 100 mg/4 mL single-dose vial
- Dose
- 2 mg/kg for a 30 kg patient = 60 mg
- Vials used
- 1× 100 mg vial
- Administered
- 60 mg
- Discarded
- 40 mg
Two claim lines required.
Line 1: J9271 × 60 units (no JZ, no JW — it’s the administered portion of a partially-wasted vial; the line itself doesn’t need a waste modifier because the wasted portion is reported separately).
Line 2: J9271 × 40 units with
JW for the discarded amount.
Pediatric weight-based dosing is the canonical JW scenario. Adult flat-dose — the case for most billed Keytruda — almost never produces waste.
Briumvi loading dose
J2329 / ublituximab / 1 mg = 1 unit
Apply JZ
- Vial size
- 150 mg/6 mL single-dose vial (current marketed presentation)
- Dose
- Day 1: 150 mg loading; Day 15: 450 mg
- Day 15 vials used
- 3× 150 mg vials = 450 mg
- Administered
- 450 mg
- Discarded
- 0 mg
JZ on the J2329 line. Briumvi is a textbook adult flat-dose drug; with whole-vial counts the JW path is rare. The full Briumvi reference page is at
/drugs/briumvi.
2026 rule updates and what changed
The JZ requirement rolled out in stages: voluntary use in 2023, mandatory use beginning July 1, 2023, claims-editing enforcement in 2024. As of 2026:
- Manufacturer refund process under Section 1847A(h). Manufacturers of single-dose-container drugs are subject to refund liability when discarded amounts (as reported on JW claims) exceed the statutory threshold for the drug. The 2025-2026 implementation has continued to add drugs to the published refund list each quarter; the discarded percentage threshold is generally 10% (with some drugs at 35%).
- Modifier reporting accuracy is enforced. Practices that systematically under-report waste (using JZ when JW would apply) increase the manufacturer’s reported discarded percentage, which can trigger a refund. Conversely, over-reporting waste creates audit exposure. The 2026 OIG work plan explicitly references discarded-drug billing accuracy.
- Medicare Advantage alignment. Most Medicare Advantage plans adopted the JZ/JW requirement in alignment with CMS edits. Some MA plans implemented their own claim-edit timeline; check the plan policy bulletin if you see modifier-related denials on MA claims.
- Commercial payers. Adoption is uneven. Major commercial payers have aligned for most large-volume drugs, but plan-by-plan variation exists. The safe default for large national payers is to bill JZ as if it were Medicare; for regional plans, verify in policy.
Common JZ-related denials and how to fix them
| Denial pattern | What it means | Fix |
|---|
| Missing modifier |
JZ or JW required for this drug; claim returned as unprocessable. |
Add JZ (zero waste) or JW (waste reported on separate line). Resubmit. No appeal needed. |
| Modifier inconsistent with units |
JW reported but billed units appear to match a whole-vial-fit dose, or JZ reported on a partial-vial dose without a paired JW line. |
Recompute: vial-size × vials drawn vs. dose administered. If they match, JZ. If not, the difference is waste — bill on a separate line with JW. |
| JZ + JW same line |
Both modifiers cannot coexist on the same claim line. |
Split into two lines: one for administered units, one for discarded units with JW. |
| JZ on multi-dose vial drug |
The drug’s formulation is multi-dose; JZ does not apply. |
Remove JZ. Verify the FDA SPL formulation; multi-dose vials are exempt from JZ/JW. |
| JZ on Part D claim |
The drug is on the Self-Administered Drug exclusion list and was billed under the pharmacy benefit. |
Remove JZ; pharmacy-benefit claims do not use the JW/JZ framework. Confirm the patient’s benefit channel before re-submitting. |
Documentation requirement. When billing with JZ, the patient’s medical record must support that the entire vial was administered with no discarded amount. The CMS guidance is that claims may be subject to medical-record review; documentation should show vial size used, total drug administered, and (where applicable) any waste amount. The same documentation underpins JW claims with the additional line-item recording of the discarded volume.
Frequently asked questions
When is the JZ modifier required?
Append JZ to Medicare Part B drug claims when the drug is administered from a single-dose container and zero amount was discarded. CMS began enforcing claims edits for the JZ requirement in 2024. The modifier applies regardless of whether the drug was billed at the full vial size or a partial-dose calculation, as long as no actual amount was wasted.
What is the difference between JZ and JW?
JZ indicates zero drug was discarded from a single-dose container. JW indicates that an amount of drug was discarded and is being billed for. Both modifiers apply only to single-dose-container drugs — never to multi-dose vials. They cannot appear on the same claim line; if part of a vial is wasted and part is administered, separate claim lines are required.
Does JZ apply to multi-dose vials?
No. JZ and JW apply only to drugs from single-dose containers (single-dose vials, single-dose syringes, single-dose ampules). Multi-dose vials are exempt because the remaining drug stays available for subsequent patients. Common multi-dose drugs in specialty billing include some immunoglobulins and certain biologics — check the FDA SPL label for the formulation.
Does JZ apply to commercial payers?
JZ is a CMS modifier required on Medicare Part B claims. Many commercial payers and Medicare Advantage plans have adopted the same requirement to align with CMS edits, but commercial requirements vary by plan and contract. Verify with the payer before submission; treating commercial claims like Medicare claims for JZ is the safe default and is what most billing systems are configured to do.
What happens if I forget to add JZ?
CMS contractors began returning claims as unprocessable when JZ or JW was missing on single-dose-container drug claims after the 2024 enforcement date. The denial typically appears as a CARC code indicating the modifier is missing or invalid. Resubmit with the appropriate modifier; no formal appeal is required for modifier-omission denials.
Related references
Sources
- CMS, Internet-Only Manual Publication 100-04 (Medicare Claims Processing Manual), Chapter 17, §40 — Discarded Drugs and Biologicals. (Authoritative source for modifier definition and applicability.)
- CMS, MM12877 / Transmittal 11842 — JZ Modifier Required for No Discarded Amounts of Drugs and Biologicals from Single-Dose Containers or Single-Use Packages.
- Section 1847A(h) of the Social Security Act — Manufacturer refund for discarded amounts of single-dose-container drugs.
- HCPCS Level II Long Descriptors, current calendar year — Modifier descriptions JZ and JW.
- OIG Work Plan, current year — Discarded drug billing accuracy review item.
All sources are publicly available federal publications. We do not paywall the underlying citations and we link to them where possible. The methodology by which we resolve source disagreements is described in the Methodology.
Editorial review & sourcing
Reviewed by
Catherine Rose, CPC — Subject Matter Expert, Medical Billing & Coding. Corporate trainer at Elevance Health; expert witness in revenue-cycle and medical-billing matters.
Last reviewed
May 2, 2026
Update triggers
CMS modifier policy change, OIG work-plan finding, payer-policy alignment shift, reader-reported correction. Reviewed pages additionally re-reviewed at minimum annually. See
review cadence.
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