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HCPCS J1809 · Level II · Part B drug

HCPCS J1809: Injection, fosdenopterin, 0.1 mg

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Data effective
Data currency: ASP payment limits October 2026 (effective October 1, 2026); MUE and NCCI edits 2026 Q4 (effective October 1, 2026); OPPS Addendum B July 2026 (effective July 1, 2026). Next CMS release: January 1, 2027 (ASP, MUE, NCCI and OPPS quarterly updates).

Key facts for J1809

Billing unit
0.1 MG
Inj, fosdenopterin, 0.1mg
ASP payment limit
$17.736
October 2026; +0.0% vs July 2026
Practitioner MUE
none published
CMS publishes no MUE for this code
OPPS status
SI K
APC 0884
NCCI exposure
no PTP pairs
Coverage articles
0
none list this code

TL;DR

HCPCS J1809 is the Level II code for Injection, fosdenopterin, 0.1 mg, billed per 0.1 MG. The Medicare Part B ASP payment limit for October 2026 is $17.736 per billing unit, up 0.0% from July 2026. Under OPPS it carries status indicator K in APC 0884. With a 1 mg billing unit, a single administration can be hundreds of units; the unit count on the claim must equal the milligrams given, and rounding rules for partial units follow the contractor's guidance. The ASP crosswalk maps 1 NDC to it, sold as Nulibry by Sentynl Therapeutics, Inc.. No current Billing and Coding Article lists J1809, so coverage follows the FDA label, compendia and any applicable NCD.

Medicare Part B payment limit (ASP)

CMS sets the Part B payment limit for J1809 at $17.736 per 0.1 MG for October 2026, derived from manufacturer average sales price plus 6%, compared with $17.736 in July 2026. Beneficiary coinsurance is 20%.

ASP payment limits for J1809
QuarterPayment limitPerCoinsurance
October 2026$17.7360.1 MG20%
July 2026$17.7360.1 MG—
Source: CMS Medicare Part B Drug Payment Limit File. Commercial and Medicaid payers set their own rates.

NDC to HCPCS billing-unit conversion

The October 2026 ASP crosswalk maps 1 NDC from 1 labeler to J1809. Report the NDC in the claim's drug segment and bill the number of J1809 units that equals the quantity administered divided by 0.1 MG; the last column gives units per full package.

NDCs that crosswalk to J1809
NDCDrug nameLabelerPackage sizeBilling units / package
42358-0295-01NulibrySentynl Therapeutics, Inc.1 × 195

Medically Unlikely Edits (MUE)

CMS does not publish an MUE for J1809 in the 2026 Q4 tables. Some MUE values are confidential and applied without publication, so unit limits can still deny; document the dose and the units calculation on every claim.

NCCI edits and add-on relationships

No active practitioner PTP pair lists J1809 as a column-1 or column-2 code in v323r0. Drug supply codes are rarely bundled; the administration codes billed with them are where PTP edits usually apply.

J1809 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Medicare coverage articles

No current Billing and Coding Article lists J1809 in its HCPCS table. Coverage then follows the drug's FDA label, compendia and any National Coverage Determination; check the Medicare Coverage Database before administering off-label.

Hospital outpatient (OPPS) status

In the July 2026 OPPS Addendum B, J1809 carries status indicator K and is assigned to APC 0884, with a published national unadjusted payment of $17.74. Status K means the drug is paid separately under OPPS at the ASP-based rate rather than packaged into the procedure.

Common denials for J1809 and how to prevent them

CARC 16 · M119

NDC missing, invalid or not matched to the HCPCS code

CARC 151 · N362

units billed exceed the MUE for the date of service

CARC 50 · N115

diagnosis not covered by the applicable coverage article or LCD

How QuickIntell checks J1809 before the claim leaves

QuickCode validates the NDC-to-unit conversion against the current ASP crosswalk, checks units against every published MUE setting and flags PTP and add-on conflicts on the same claim. QuickRCM routes CARC 16, 151 and 50 denials on drug lines with the matching coverage article attached so the appeal starts with evidence.

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Frequently asked questions — HCPCS J1809

What does HCPCS code J1809 describe?

J1809 is defined by CMS as "Injection, fosdenopterin, 0.1 mg". Each billing unit represents 0.1 MG, so the units reported on the claim must equal the dose administered divided by that unit.

What is the Medicare reimbursement for J1809 in October 2026?

The ASP-based payment limit is $17.736 per 0.1 MG, with 20% beneficiary coinsurance. Medicare Administrative Contractors apply this limit; commercial payers use their own fee schedules. The July 2026 limit was $17.736.

Which NDCs map to J1809?

The October 2026 ASP crosswalk lists 1 NDC from 1 labeler: Nulibry (Sentynl Therapeutics, Inc.). For example NDC 42358-0295-01 is a 1 package equal to 95 billing units. The crosswalk's billing-units-per-package figure converts each package into J1809 units.

Does J1809 have NCCI bundling edits?

No active practitioner PTP pairs list J1809 as a column-1 or column-2 code in the v323r0 release. Unit limits (MUE) and medical-necessity coverage rules still apply.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-02. Verify against the primary file before billing or contracting decisions.

Disclaimer

This page is an operational reference compiled from CMS publications: the Medicare Part B drug payment limit and NDC crosswalk files, NCCI MUE and add-on edit tables, aggregate PTP statistics, OPPS Addendum B and the Medicare Coverage Database. Payment limits are Medicare national amounts; commercial and Medicaid payers differ. CPT codes are shown as numbers only; CPT descriptors are copyright AMA. Nothing here is legal, clinical or billing advice.