J1326
J1326 – Inj, zolbetuximab-clzb, 2 mg · NDC Crosswalk & Billing Units
HCPCS Level II J-code · Medicare Part B drug billing
J-code
● 2 NDCs crosswalked per 2 MG $33.924/unit ASP+6%
📋 J1326 summary
J1326 is a HCPCS Level II J-code used to bill zolbetuximab-clzb, 2 mg, billed per 2 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 J1326: Vyloy
Code J1326
Billing unit 2 MG Payment limit $33.924/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 codeJ1326
DescriptorInj, zolbetuximab-clzb, 2 mg
Billing unit2 MG
Payment limit / unit$33.924
Est. ASP / unit$32.004 est.
Mapped NDCs2
Data periodQ3 2026
Last updated2026-08-20
💊 About Zolbetuximab DRUG GUIDE
Vyloy (zolbetuximab-clzb) is used alongside fluoropyrimidine- and platinum-based chemotherapy as a first-line treatment for adults with locally advanced unresectable or metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma — meaning stomach or junction-of-stomach-and-esophagus cancer that has spread or cannot be surgically removed.
The cancer must test negative for HER2 and must test positive for a protein called CLDN18.2 (claudin 18.2) using an FDA-approved diagnostic test.Vyloy is always given together with chemotherapy — never on its own — and is intended for adults who have not yet received prior treatment for their advanced cancer.
Clinical overview from our editorial drug guide for Zolbetuximab. 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
$33.924
Est. ASP / unit
$32.004 est.
Est. after 2% sequester
$33.246
HCPCS dosage
2 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.
🧮 Dosing & billing-units calculator HCPCS UNITS
One billing unit of J1326 = 2 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 J1326 WITH EST. MEDICARE PAY
2 NDCs map to J1326. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($33.924/unit) × that package's bill units.
| NDC (11-digit) | Drug | Labeler | Package | Strength | Bill units | Est. pay / pkg | NADAC / unit | Status | Source |
|---|---|---|---|---|---|---|---|---|---|
| 00469-3425-10 | VYLOY ZOLBETUXIMAB 20 mg/mL INJECTION, POWDER, FOR SUSPENSION | Astellas | 1 VIAL in 1 BOX (0469-3425-10) / 5 mL in... | 20 mg/mL | 50 | $1,696.20 | — | ● Active | CMS + PDAC |
| 00469-4425-30 | VYLOY ZOLBETUXIMAB 20 mg/mL INJECTION, POWDER, FOR SUSPENSION | Astellas | 1 VIAL in 1 BOX (0469-4425-30) / 15 mL in... | 20 mg/mL | 150 | $5,088.60 | — | ● Active | CMS + PDAC |
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
$12.35M
Claims
834
Beneficiaries
278
Spend / beneficiary
$44,423.91
Spend / claim
$14,807.97
Trend by period
Where J1326 ranks among Part B drugs · 2026 (Q1) · neighbors ±5
Total spending — #161 of 824
#156
DOCIVYX J9172
$12.62M
#157
ENJAYMO J1302
$12.53M
#158
KANJINTI Q5117
$12.45M
#159
MONJUVI J9349
$12.35M
#160
BAVENCIO J9023
$12.35M
#161
VYLOY J1326
$12.35M
#162
POSFREA J2468
$12.27M
#163
XEMBIFY J1558
$12.01M
#164
ALYGLO J1552
$11.88M
#165
RITUXAN HYCELA J9311
$11.87M
#166
LUNSUMIO VELO* J9350
$11.74M
Total claims — #393 of 824
#388
PIPERACILLIN-TAZOBAC... J2543
873
#389
AMIKACIN SULFATE J0278
865
#390
LUMASON Q9950
846
#391
RELESE, PER SQ CM** Q4257
843
#392
LEUPROLIDE DEPOT* J1954
839
#393
VYLOY J1326
834
#394
DUOPA J7340
832
#395
TREMFYA ONE-PRESS* J1628
820
#396
FABRAZYME J0180
810
#397
DEPO-ESTRADIOL J1000
810
#398
CLEOCIN PHOSPHATE* J0736
808
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) | $12.35M | 278 | 834 | $44,423.91 | $14,807.97 |
| 2025 (Q1-Q4) | $21.54M | 335 | 1,343 | $64,301.54 | $16,039.48 |
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
$7.77M
Medicare paid
$6.1M
Submitted services
252,848
Denial rate
8.6%
Allowed / service
$33.65
Submitted charges
$22.95M
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.
📊 What bills under J1326
J-codes are billing codes often used for drugs billed under the medical benefit. This connects the billing code to the NDC package records it covers, by ingredient and labeler.
NDC products by ingredient
NDC products by labeler
🗃️ 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
Not available in current dataset
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 + DMEPDAC (PDAC)
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.
❓ J1326 billing FAQ
What is HCPCS code J1326?
J1326 is a HCPCS Level II J-code used to bill Inj, zolbetuximab-clzb, 2 mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J1326?
One unit of J1326 represents 2 MG. Report the number of units equal to the dose administered divided by 2 MG.
How many units of J1326 should I bill?
Divide the dose administered by the code's unit size (2 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 J1326?
The Medicare Part B payment limit is $33.924 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $33.246 per unit. Payment limits are revised quarterly.
Which NDCs bill under J1326?
2 NDCs currently map to J1326 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 J1326 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.