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J1809

J1809 – Inj, fosdenopterin, 0.1mg · NDC Crosswalk & Billing Units

HCPCS Level II J-code · Medicare Part B drug billing
J-code ● 1 NDC crosswalked per 0.1 MG $17.736/unit ASP+6%

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Compiled from public FDA, CMS, DailyMed, NADAC, and related drug data sources. Editorial policy

📋 J1809 summary

J1809 is a HCPCS Level II J-code used to bill fosdenopterin, 0.1mg, billed per 0.1 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 J1809: Nulibry

Code J1809 Billing unit 0.1 MG Payment limit $17.736/unit NDC-Crosswalk 1 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 codeJ1809
DescriptorInj, fosdenopterin, 0.1mg
Billing unit0.1 MG
Payment limit / unit$17.736
Est. ASP / unit$16.732 est.
Mapped NDCs1
Data periodQ3 2026
Last updated2026-09-20

🧾 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
$17.736
Est. ASP / unit
$16.732 est.
Est. after 2% sequester
$17.381
HCPCS dosage
0.1 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.

🧮 Dosing & billing-units calculator HCPCS UNITS

One billing unit of J1809 = 0.1 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 J1809 WITH EST. MEDICARE PAY

1 NDC map to J1809. Bill units = how many HCPCS units one package represents. Est. pay / pkg = payment limit ($17.736/unit) × that package's bill units.
NDC (11-digit)DrugLabelerPackageStrength Bill units Est. pay / pkg NADAC / unit StatusSource
42358-0295-01 Nulibry fosdenopterin hydrobromide 9.5 mg/1 INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION Sentynl 1 VIAL, SINGLE-DOSE in 1 CARTON (42358-295... 9.5 mg/1 95 $1,684.92 — ● 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

No reportable public Medicare utilization was found for J1809. This is expected for newer codes, low-volume drugs, or codes whose use is billed under another code. CMS also hides any figure covering fewer than 11 patients (a privacy rule), so small-volume use may exist but isn't publishable. Utilization and spend appear here automatically once CMS publishes reportable data for this code.

📊 What bills under J1809

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
fosdenopterin hydrobromide 1
NDC products by labeler
Sentynl Therapeutics, Inc. 1

🗃️ 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 2026-09-20
NDC ↔ HCPCS crosswalk
CMS ASP NDC-HCPCS crosswalk + DMEPDAC (PDAC)
1 NDC 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
No reportable utilization
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.

❓ J1809 billing FAQ

What is HCPCS code J1809?
J1809 is a HCPCS Level II J-code used to bill Inj, fosdenopterin, 0.1mg under Medicare Part B and most medical (not pharmacy) benefits.
What is the billing unit for J1809?
One unit of J1809 represents 0.1 MG. Report the number of units equal to the dose administered divided by 0.1 MG.
How many units of J1809 should I bill?
Divide the dose administered by the code's unit size (0.1 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 J1809?
The Medicare Part B payment limit is $17.736 per unit (Q3 2026), based on ASP + 6%. After the 2% sequester the effective payment is about $17.381 per unit. Payment limits are revised quarterly.
Which NDCs bill under J1809?
1 NDC currently map to J1809 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 J1809 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.