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HCPCS J1428 · Level II · Part B drug

J1428: eteplirsen (Exondys 51), HCPCS Level II J code

Compiled from CMS files by the QuickIntell RCM Editorial Team · Data effective · Method: reference methodology · Report a data correction

Data currency: OPPS Addendum B: October 2026 (effective October 1, 2026); OPPS NDC-HCPCS crosswalk: October 2026 (effective October 1, 2026); NCCI MUE tables: 2026 Q4 (effective October 1, 2026); NCCI PTP edits: v323r0 (2026 Q4) (effective October 1, 2026); ASC Addendum BB (covered ancillary services): October 2026 (effective October 1, 2026). Next CMS release: January 1, 2027 (quarterly update).

Key facts for J1428

Billing unit
10 MG
Inj, eteplirsen, 10 mg
OPPS payment rate
$167.453
no ASP limit; SI K, October 2026
Practitioner MUE
450
MAI 3
OPPS status
SI K
APC 9484
NCCI exposure
no PTP pairs
Coverage articles
0
none list this code

TL;DR

HCPCS J1428 is the Level II code for Injection, eteplirsen, 10 mg, billed per 10 MG. CMS publishes no ASP payment limit for it; hospital outpatient departments are paid separately under OPPS (status indicator K, $167.453 per billing unit in October 2026). The practitioner MUE allows up to 450 units per date of service (MAI 3). The 10 mg billing unit means doses are reported in multiples of ten milligrams, with any remainder rounded per contractor policy; mismatched units against the NDC quantity trigger MUE and NDC-unit edits. The OPPS crosswalk maps 2 NDCs to it, sold as Exondys 51 by Sarepta Therapeutics, Inc. No current Billing and Coding Article lists J1428, so coverage follows the FDA label, compendia and any applicable NCD.

Medicare payment: OPPS rate (no ASP limit)

J1428 does not appear in the October 2026 Part B ASP payment limit file. CMS pays it separately to hospital outpatient departments under OPPS with status indicator K in APC 9484, at a national unadjusted rate of $167.453 per 10 MG. Status K is a separately paid, non-pass-through drug or biological, including therapeutic radiopharmaceuticals. In a physician office the Medicare contractor prices the drug, often from invoice; commercial and Medicaid payers set their own rates.

NDC to HCPCS billing-unit conversion

The October 2026 OPPS crosswalk maps 2 NDCs from 1 labeler to J1428. Report the NDC in the claim's drug segment and bill the number of J1428 units that equals the quantity administered divided by 10 MG; the last column gives units per full package.

NDCs that crosswalk to J1428
NDCDrug nameLabelerPackage sizeBilling units / package
60923-0284-10Exondys 51Sarepta Therapeutics, Inc.10 × 150
60923-0363-02Exondys 51Sarepta Therapeutics, Inc.2 × 110

Medically Unlikely Edits (MUE)

CMS publishes 3 MUE values for J1428. For practitioners the limit is 450 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 J1428 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services4503 Date of Service Edit: ClinicalPrescribing Information
Facility outpatient hospital4503 Date of Service Edit: ClinicalPrescribing Information
DME supplier03 Date of Service Edit: ClinicalCMS Policy

MUE for J1428 in every setting opens the lookup with this code filled in, next to any other code on the same claim.

NCCI edits and add-on relationships

No active practitioner PTP pair lists J1428 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.

The counts above are exposure, not answers for a specific claim. Check J1428 against another code to see whether a given pair bundles, which code is paid and whether a modifier can separate them.

J1428 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 J1428 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 October 2026 OPPS Addendum B, J1428 carries status indicator K and is assigned to APC 9484, with a published national unadjusted payment of $167.453. Status K means the drug is paid separately under OPPS rather than packaged into the procedure.

Ambulatory surgical center (ASC) payment

In the October 2026 ASC Addendum BB (covered ancillary services), J1428 carries payment indicator K2, which CMS defines as "Drugs, biologicals, and radiopharmaceuticals paid separately when provided integral to a surgical procedure on ASC list; payment based on OPPS rate". The national ASC payment is $167.45 per 10 MG, paid only when the drug is furnished integral to a covered surgical procedure.

Common denials for J1428 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 J1428 before the claim leaves

QuickCode validates the NDC-to-unit conversion against the current OPPS NDC-HCPCS 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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In QuickIntell research

Frequently asked questions — HCPCS J1428

What does HCPCS code J1428 describe?

J1428 is defined by CMS as "Injection, eteplirsen, 10 mg". Each billing unit represents 10 MG, so the units reported on the claim must equal the dose administered divided by that unit.

Is J1428 a CPT code?

No. J1428 is a HCPCS Level II code, the letter-plus-four-digit set CMS maintains for drugs such as eteplirsen (Exondys 51); CPT codes are five-character codes maintained by the AMA. On a Part B claim J1428 reports the drug itself in 10 mg units, and the administration is billed on its own line.

What does Medicare pay for J1428 in a hospital outpatient department?

J1428 has no Part B ASP limit; the October 2026 OPPS Addendum B pays it separately under status K, APC 9484, at $167.453 per 10 MG, and ASC Addendum BB gives it payment indicator K2 at $167.45.

How many units of J1428 can be billed per day?

The practitioner Medically Unlikely Edit is 450 units per date of service with adjudication indicator 3 (Date of Service Edit: Clinical). MAI 3 edits can be appealed with documentation that the units were medically reasonable. CMS cites "Prescribing Information" as the rationale.

Which NDCs map to J1428?

The October 2026 OPPS crosswalk lists 2 NDCs from 1 labeler: Exondys 51 (Sarepta Therapeutics, Inc.). For example NDC 60923-0284-10 (package size 10) equals 50 billing units of J1428.

Does J1428 have NCCI bundling edits?

No active practitioner PTP pairs list J1428 as a column-1 or column-2 code in the v323r0 release.

Sources

Every figure on this page is taken from the CMS publications below, as released by the Centers for Medicare & Medicaid Services. Projection built 2026-10-10. Verify against the primary file before billing or contracting decisions. The reference methodology explains how each figure is computed from these files.

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, ASC Addendum BB and the Medicare Coverage Database. Payment limits and rates 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.

Found a figure that does not match the CMS file? Report a data correction with the CMS file and the value you expected; the request reaches the editorial team through the contact form.