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HCPCS J1743 · Level II · Part B drug

HCPCS J1743: Injection, idursulfase, 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 J1743

Billing unit
1 MG
Idursulfase injection
ASP payment limit
$572.171
October 2026; +0.4% vs July 2026
Practitioner MUE
66
MAI 3
OPPS status
SI K
APC 9045
NCCI exposure
no PTP pairs
Coverage articles
0
none list this code

TL;DR

HCPCS J1743 is the Level II code for Injection, idursulfase, 1 mg, billed per 1 MG. The Medicare Part B ASP payment limit for October 2026 is $572.171 per billing unit, up 0.4% from July 2026. The practitioner MUE allows up to 66 units per date of service (MAI 3). Under OPPS it carries status indicator K in APC 9045. 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 Elaprase by Takeda Pharmaceuticals America, Inc.. No current Billing and Coding Article lists J1743, 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 J1743 at $572.171 per 1 MG for October 2026, derived from manufacturer average sales price plus 6%, compared with $570.043 in July 2026. Beneficiary coinsurance is 20%.

ASP payment limits for J1743
QuarterPayment limitPerCoinsurance
October 2026$572.1711 MG20%
July 2026$570.0431 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 J1743. Report the NDC in the claim's drug segment and bill the number of J1743 units that equals the quantity administered divided by 1 MG; the last column gives units per full package.

NDCs that crosswalk to J1743
NDCDrug nameLabelerPackage sizeBilling units / package
54092-0700-01ElapraseTakeda Pharmaceuticals America, Inc.3 × 16

Medically Unlikely Edits (MUE)

CMS publishes 3 MUE values for J1743. For practitioners the limit is 66 units per date of service with adjudication indicator 3, a date-of-service clinical edit: units above the limit deny but can be paid on appeal with documentation that the quantity was medically reasonable.

MUE values for J1743 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services663 Date of Service Edit: ClinicalClinical: Data
Facility outpatient hospital663 Date of Service Edit: ClinicalClinical: Data
DME supplier03 Date of Service Edit: ClinicalCMS Policy

NCCI edits and add-on relationships

No active practitioner PTP pair lists J1743 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.

J1743 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 J1743 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, J1743 carries status indicator K and is assigned to APC 9045, with a published national unadjusted payment of $570.04. Status K means the drug is paid separately under OPPS at the ASP-based rate rather than packaged into the procedure.

Common denials for J1743 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 J1743 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 J1743

What does HCPCS code J1743 describe?

J1743 is defined by CMS as "Injection, idursulfase, 1 mg". Each billing unit represents 1 MG, so the units reported on the claim must equal the dose administered divided by that unit.

What is the Medicare reimbursement for J1743 in October 2026?

The ASP-based payment limit is $572.171 per 1 MG, with 20% beneficiary coinsurance. Medicare Administrative Contractors apply this limit; commercial payers use their own fee schedules. The July 2026 limit was $570.043.

How many units of J1743 can be billed per day?

The practitioner Medically Unlikely Edit is 66 units per date of service with adjudication indicator 3 (3 Date of Service Edit: Clinical). MAI 3 edits can be appealed with documentation that the units were medically reasonable. CMS cites "Clinical: Data" as the rationale.

Which NDCs map to J1743?

The October 2026 ASP crosswalk lists 1 NDC from 1 labeler: Elaprase (Takeda Pharmaceuticals America, Inc.). For example NDC 54092-0700-01 is a 3 package equal to 6 billing units. The crosswalk's billing-units-per-package figure converts each package into J1743 units.

Does J1743 have NCCI bundling edits?

No active practitioner PTP pairs list J1743 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 2026-10-01. 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.