J9354
J9354 – Injection, ado-trastuzumab emtansine, 1 mg · NDC Crosswalk & Billing Units
HCPCS Level II J-code · Medicare Part B drug billing
J-code
● 2 NDCs crosswalked per 1 MG $43.626/unit ASP+6%
📋 J9354 summary
J9354 is a HCPCS Level II J-code used to bill ado-trastuzumab emtansine, 1 mg, billed per 1 MG. The number of billing units to report depends on the dose administered and the NDC/package billed — use the calculator below.
Brand names associated with J9354: Kadcyla
Code J9354
Billing unit 1 MG Payment limit $43.626/unit NDC-Crosswalk 2
Quarter Q3 2026
RxCUI Atlas Trace the drug concept →
⚠ An NDC↔HCPCS crosswalk and a published payment limit do not guarantee payer coverage or payment. Always verify the current payer policy and claim format before billing.
🗂️ Key billing facts
HCPCS codeJ9354
DescriptorInjection, ado-trastuzumab emtansine, 1 mg
Billing unit1 MG
Payment limit / unit$43.626
Est. ASP / unit$41.157 est.
Mapped NDCs2
Data periodQ3 2026
Last updated2026-08-20
💊 About Ado-trastuzumab Emtansine Injection DRUG GUIDE
Kadcyla (ado-trastuzumab emtansine) is used on its own to treat HER2-positive metastatic breast cancer in adults who have already received trastuzumab and a taxane chemotherapy, either together or separately.
It is used when cancer has come back or spread, or when the disease returned within six months of finishing earlier treatment.Kadcyla is also used as adjuvant (after-surgery) treatment for HER2-positive early breast cancer in patients who still had remaining cancer after completing neoadjuvant (pre-surgery) treatment with a taxane and trastuzumab.
Patients must be tested for HER2 overexpression or gene amplification using an FDA-authorized test before starting Kadcyla.
Clinical overview from our editorial drug guide for Ado-trastuzumab Emtansine Injection. For billing reference, see the sections above.
🧾 Billing & reimbursement HCPCS · CMS · EFF. Q3 2026
📅 Payment limits effective Q3 2026 — from the CMS Medicare Part B Payment Limit File (revised quarterly).
Medicare payment limit / unit
$43.626
Est. ASP / unit
$41.157 est.
Est. after 2% sequester
$42.753
HCPCS dosage
1 MG
The CMS payment limit is the Medicare Part B drug allowance (ASP + 6%, statutory). After the 2% federal sequester the effective payment is ≈ ASP + 4.3%; estimated ASP = payment limit ÷ 1.06. Source: CMS Medicare Part B Payment Limit File (quarterly), Q3 2026.
Full HCPCS code details (official CMS record)
Long descriptionInjection, ado-trastuzumab emtansine, 1 mg
CoverageC — Carrier/MAC judgment
Pricing indicator51 — Drug — priced under the ASP methodology
Type of service1 — Medical care
BETOS-2O1D
ASC payment groupYY
Action codeN — No maintenance this year
Effective date2014-01-01
Date added2014-01-01
Source: CMS HCPCS Level II code file (imported via admin).
🧮 Dosing & billing-units calculator HCPCS UNITS
One billing unit of J9354 = 1 mg. Enter a regimen to convert dose → billing units and project a full course.
Billing units = dose ÷ HCPCS unit size. Most payers require whole units — round per the payer's policy. “Est. Medicare pay” uses the current payment limit. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (JZ when none is discarded) where allowed. Always verify payer-specific rounding before billing.
🔁 NDCs that bill under J9354 WITH EST. MEDICARE PAY
2 NDCs map to J9354. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($43.626/unit) × that package's bill units.
| NDC (11-digit) | Drug | Labeler | Package | Strength | Bill units | Est. pay / pkg | NADAC / unit | Status | Source |
|---|---|---|---|---|---|---|---|---|---|
| 50242-0087-01 | KADCYLA ADO-TRASTUZUMAB EMTANSINE 20 mg/mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Genentech, | 1 VIAL, SINGLE-USE in 1 CARTON (50242-087-... | 20 mg/mL | 160 | $6,980.16 | — | ● Active | CMS ASP |
| 50242-0088-01 | KADCYLA ADO-TRASTUZUMAB EMTANSINE 20 mg/mL INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION | Genentech, | 1 VIAL, SINGLE-USE in 1 CARTON (50242-088-... | 20 mg/mL | 100 | $4,362.60 | — | ● Active | CMS ASP |
NDC→HCPCS mappings come from the CMS ASP NDC-HCPCS crosswalk; additional DME MAC / DMEPOS mappings come from PDAC and are labeled separately. NADAC from CMS (weekly). “Status” reflects the product's marketing / obsolete flag in the NDC directory. Presence or absence here does not determine Medicare coverage. Linked NDCs open the full product page.
📊 Medicare utilization & spend CMS · PART B · 2026 (Q1)
Period
Total Part B spend
$32.97M
Claims
3,061
Beneficiaries
1,117
Spend / beneficiary
$29,517.85
Spend / claim
$10,771.46
Trend by period
Where J9354 ranks among Part B drugs · 2026 (Q1) · neighbors ±5
Total spending — #91 of 824
#86
NULOJIX J0485
$34.95M
#87
TYSABRI J2323
$34.71M
#88
BREYANZI Q2054
$34.18M
#89
RYBREVANT J9061
$33.53M
#90
CYRAMZA J9308
$33.32M
#91
KADCYLA J9354
$32.97M
#92
BENLYSTA J0490
$32.83M
#93
TRUXIMA Q5115
$32.81M
#94
VYEPTI J3032
$31.97M
#95
ENVARSUS XR J7503
$31.82M
#96
ARALAST NP* J0256
$31.72M
Total claims — #267 of 824
#262
GLUCAGEN* J1610
3,369
#263
CYRAMZA J9308
3,313
#264
PROHANCE MULTIPACK A9576
3,254
#265
SARCLISA J9227
3,200
#266
ULTOMIRIS J1303
3,104
#267
KADCYLA J9354
3,061
#268
XIAFLEX J0775
3,016
#269
HYQVIA J1575
3,013
#270
STIMUFEND Q5127
3,002
#271
PHENERGAN* J2550
2,981
#272
ONIVYDE J9205
2,939
Top Medicare Part B drugs by the selected metric. Click any drug to open its J-code page. Source: CMS Medicare Quarterly Part B Spending by Drug.
Full breakdown by period (2)
| Period | Total spend | Beneficiaries | Claims | $/beneficiary | $/claim |
|---|---|---|---|---|---|
| 2026 (Q1) | $32.97M | 1,117 | 3,061 | $29,517.85 | $10,771.46 |
| 2025 (Q1-Q4) | $143.96M | 2,112 | 13,412 | $68,161.03 | $10,733.38 |
Provider-administered (Part B) spend, calculated for the whole HCPCS code (CMS does not publish Medicare spend per individual NDC). Self-administered use is covered under Part D instead. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part B Spending by Drug (data.cms.gov), updated quarterly.
📈 Medicare Part B claims detail CMS PSPS · 2024
Calendar-year 2024 Medicare Part B fee-for-service activity for this HCPCS code, summed across all carriers, localities and specialties (CMS Physician/Supplier Procedure Summary). A “service” is one billed line/unit — not one claim — so counts run higher than claim counts.
Allowed charges
$51.29M
Medicare paid
$39.86M
Submitted services
1,286,511
Denial rate
3.5%
Allowed / service
$41.31
Submitted charges
$125.89M
Source: CMS Physician/Supplier Procedure Summary (PSPS), CY2024 — Medicare Part B carrier + DME fee-for-service claims (excludes Medicare Advantage). Figures are for the whole HCPCS code, which may cover uses beyond this drug. ⚠ CMS hides any figure covering fewer than 11 patients (a privacy rule), so totals — especially denials and low-volume codes — run a little low.
🗃️ Data sources & freshness
Every figure on this page is computed from public datasets. Here's what each section draws on and how current it is.
HCPCS code & descriptor
CMS HCPCS Level II code file
Loaded
Payment limit & billing unit
CMS Medicare Part B ASP Pricing File (quarterly)
Q3 2026 · as of 2026-08-20
NDC ↔ HCPCS crosswalk
CMS ASP NDC-HCPCS crosswalk
2 NDCs mapped
NADAC acquisition cost
CMS National Average Drug Acquisition Cost (weekly)
Not available for mapped NDCs
Utilization & spend
CMS Part B Spending by Drug · PSPS · Physician & Other Practitioners
Latest data year 2026
Figures are estimates for reference and may lag the source files. Always verify against the current CMS files and your payer's policy before submitting claims.
⚠️ Practical billing caveats
- A crosswalk is not coverage. An NDC mapping or a published payment limit does not guarantee a payer will cover or pay this code. Check the specific plan's policy.
- Units ≠ milligrams. Bill the number of HCPCS units (dose ÷ the code's unit size), not the milligram dose. Use the calculator above.
- Discarded drug. For single-dose vials, drug discarded after administration may be separately billable with modifier JW (and JZ when nothing is discarded) where the payer allows.
- Rounding & partial units. Many payers require whole units; round per the payer's policy, not automatically up.
- The code can cover more than this drug. Some HCPCS codes span multiple products or strengths — confirm the exact code for the product administered.
- Figures lag. ASP limits change quarterly and utilization data are released with a delay. Verify against the current CMS files before billing.
❓ J9354 billing FAQ
What is HCPCS code J9354?
J9354 is a HCPCS Level II J-code used to bill Injection, ado-trastuzumab emtansine, 1 mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J9354?
One unit of J9354 represents 1 MG. Report the number of units equal to the dose administered divided by 1 MG.
How many units of J9354 should I bill?
Divide the dose administered by the code's unit size (1 MG) to get the number of billing units, then round per your payer's policy. The calculator on this page converts a dose into billing units and projects a full course.
How much does Medicare pay for J9354?
The Medicare Part B payment limit is $43.626 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $42.753 per unit. Payment limits are revised quarterly.
Which NDCs bill under J9354?
2 NDCs currently map to J9354 in the CMS ASP NDC-HCPCS crosswalk. See the NDC crosswalk table above for each product, package, billing units and estimated reimbursement.
Does a crosswalk mean J9354 is covered?
No. An NDC-to-HCPCS crosswalk and a published payment limit do not guarantee coverage or payment. Coverage depends on the payer, the diagnosis and the site of care — always verify the current policy before billing.
For professional billing reference only — verify against the current CMS files before submitting claims.