Page reviewed Jun 29, 2026 · from CMS HCPCS Level II modifier definitions & the CMS Discarded Drugs policy
The four you can't skip
JZ
Zero waste (mandatory)
JW
Discarded drug (separate line)
JA
Given intravenously
JB
Given subcutaneously
Drug wastage modifiers (mandatory)
| Modifier | CMS definition | When to use | Documentation |
|---|---|---|---|
| -JZ | Zero drug amount discarded/not administered to any patient. | Required for dates of service on or after July 1, 2023 (claims unprocessable from October 1, 2023) on Part B claims for separately payable single-dose-container drugs where no portion is discarded. Optional Jan 1 - June 30, 2023. | Medical record showing the entire labeled amount was administered or otherwise no waste occurred |
| -JW | Drug amount discarded/not administered to any patient. | Append on a separate claim line representing the discarded units when a portion of a single-dose container is discarded after administering the prescribed dose. Required since January 1, 2017 (HOPPS) and uniformly across Part B since January 1, 2023. | Medical record documentation of the exact discarded amount; Single-dose vial NDC and label units |
Route-of-administration modifiers
| Modifier | CMS definition | When to use | Documentation |
|---|---|---|---|
| -JA | Administered intravenously. | Append to a drug HCPCS code when the drug was administered by intravenous push or infusion and the same code can be given by another route (typically SC). | Order specifying IV route; Administration record |
| -JB | Administered subcutaneously. | Append to a drug HCPCS code when the drug was administered subcutaneously and the same code can be given by another route (typically IV). For SAD-list drugs given SC, may trigger benefit exclusion. | Order specifying SC route; Administration record |
Medical-necessity & liability modifiers
| Modifier | CMS definition | When to use | Documentation |
|---|---|---|---|
| -KX | Requirements specified in the medical policy have been met. | Append when the supplier attests that all statutory and reasonable-and-necessary requirements specified in the related LCD have been met. KX is an affirmative attestation, not a coverage workaround. | Standard Written Order on file; Medical records substantiating each criterion in the governing LCD's 'Coverage Indications, Limitations and/or Medical Necessity' section; Supplier attestation that all LCD criteria are met |
| -GA | Waiver of liability statement issued as required by payer policy, individual case. | Append when a valid ABN has been signed by the beneficiary before service. Medicare will deny the line, and beneficiary financial liability is preserved (provider may bill the patient). | Signed Advance Beneficiary Notice of Noncoverage (CMS-R-131) on file prior to delivery/service |
| -GZ | Item or service expected to be denied as not reasonable and necessary. | Append when the supplier expects denial as not reasonable and necessary and does NOT have a signed ABN. Claim is denied automatically without complex medical review; supplier (not beneficiary) is financially liable. | — |
| -GY | Item or service statutorily excluded, does not meet the definition of any Medicare benefit or, for non-Medicare insurers, is not a contract benefit. | Append when the item or service is statutorily excluded from Medicare. Triggers automatic denial; beneficiary is liable; no ABN required. | — |
| -EY | No physician or other licensed health care provider order for this item or service. | Append to each affected HCPCS code when no qualifying provider order/prescription is on file. Items with EY must be on a separate claim from items with a compliant order. Triggers denial; beneficiary financial liability follows ABN rules. | Documentation of attempt to obtain order (where applicable) |
JW / JZ drug-wastage rules
Effective January 1, 2023, CMS uses JW (waste reported) and JZ (no waste) modifiers to calculate discarded-drug refunds under Part B. JZ became mandatory for dates of service on or after July 1, 2023, with claims returned as unprocessable from October 1, 2023 if neither JW nor JZ is present on a single-dose-container drug line. JW and JZ are mutually exclusive on the same claim line. In a multi-vial dose, one line may carry JZ (administered) and a separate line may carry JW (waste).
Claim-line order: Modifier order matters on a claim line. Pricing modifiers (NU/RR/UE/KH/KI/KJ/MS/KE) belong in the first position; KX/GA/GZ/GY/EY/BA/JA/JB/JW/JZ are informational and follow.
Frequently asked questions
- What is the difference between JW and JZ?
- JZ reports zero discarded drug; JW reports the discarded amount on a separate claim line. Both are mandatory on separately payable single-dose-container drugs (since July 1, 2023; claims are unprocessable without one). They are mutually exclusive on the same line — JZ when nothing is wasted, JW (plus JZ on the administered line) when there is waste.
- When do I use JA vs JB?
- JA = administered intravenously; JB = administered subcutaneously. For route-dependent drugs this also drives the benefit: the SC form may be self-administered (Part D) while the IV form is Part B. Use the modifier matching the route given.
- What does GZ mean and how is it different from GA?
- GZ means you expect the item to be denied as not reasonable and necessary and you do NOT have a signed ABN. GA means you expect denial and DO have a signed ABN (waiver of liability) on file. Use GA when the patient has accepted financial responsibility.
Related references
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- Source
- CMS HCPCS Level II modifier definitions (verbatim) and the CMS Discarded Drugs (JW/JZ) policy; MAC modifier references. Modifier codes/definitions are public (CMS), not CPT.
- Page last reviewed by CareCost
- Jun 29, 2026.
- Not advice
- General billing reference, not legal or billing advice. Verify against current CMS/MAC guidance.
- Spotted an error?
- Email editorial@carecostestimate.com.