J9358 — Injection, fam-trastuzumab deruxtecan-nxki, 1 mg
J9358 is a HCPCS Level II code for injection, fam-trastuzumab deruxtecan-nxki, 1 mg. It belongs to the Drugs Administered Other Than Oral Method section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Carrier judgment
Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusE
Excluded from the physician fee schedule by regulation. Payment, where it exists, comes from another fee schedule (drugs via ASP, supplies via DMEPOS, and so on).
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
Medically Unlikely Edits — units per day
The most units of J9358 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.
- practitioner
- 1000 units MAI 3 — Date of Service Edit: Clinical · CMS Policy
- outpatient
- 1000 units MAI 3 — Date of Service Edit: Clinical · CMS Policy
- DME supplier
- 1000 units MAI 3 — Date of Service Edit: Clinical · CMS Policy
The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.
The CMS record for J9358
- Long descriptor
- Injection, fam-trastuzumab deruxtecan-nxki, 1 mg
- Short descriptor
- Inj fam-trastu deru-nxki 1mg
- Added
- July 1, 2020
- BETOS
- O1E
- Pricing indicator
- 51 — Other
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Drugs.
Codes adjacent to J9358
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If J9358 is not quite right, the correct code is very often within a few positions of it.
- J9350Injection, mosunetuzumab-axgb, 1 mg
- J9351Injection, topotecan, 0.1 mg
- J9352Injection, trabectedin, 0.1 mg
- J9353Injection, margetuximab-cmkb, 5 mg
- J9354Injection, ado-trastuzumab emtansine, 1 mg
- J9355Injection, trastuzumab, excludes biosimilar, 10 mg
- J9356Injection, trastuzumab, 10 mg and hyaluronidase-oysk
- J9357Injection, valrubicin, intravesical, 200 mg
- J9359Injection, loncastuximab tesirine-lpyl, 0.075 mg
- J9360Injection, vinblastine sulfate, 1 mg
- J9361Injection, efbemalenograstim alfa-vuxw, 0.5 mg
- J9370Vincristine sulfate, 1 mg
- J9371Injection, vincristine sulfate liposome, 1 mgterminated
- J9376Injection, pozelimab-bbfg, 1 mg
- J9380Injection, teclistamab-cqyv, 0.5 mg
- J9381Injection, teplizumab-mzwv, 5 mcg
Questions about J9358
What is HCPCS code J9358?
J9358 is a HCPCS Level II code for injection, fam-trastuzumab deruxtecan-nxki, 1 mg. It sits in the Drugs Administered Other Than Oral Method section.
Does Medicare cover J9358?
The CMS HCPCS file marks J9358 as "Carrier judgment". Coverage is decided by your Medicare contractor, not by national policy. Whether this is paid depends on the LCD for your jurisdiction and on what the documentation supports.
How is J9358 paid under the physician fee schedule?
J9358 carries PFS status code E. Excluded from the physician fee schedule by regulation. Payment, where it exists, comes from another fee schedule (drugs via ASP, supplies via DMEPOS, and so on).