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HCPCS J1558 · Level II · Part B drug

HCPCS J1558: Injection, immune globulin (xembify), 100 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 J1558

Billing unit
100 MG
Inj. xembify, 100 mg
ASP payment limit
$15.20
October 2026; -0.3% vs July 2026
Practitioner MUE
480
MAI 3
OPPS status
SI K
APC 9372
NCCI exposure
no PTP pairs
Coverage articles
1
5 states

TL;DR

HCPCS J1558 is the Level II code for Injection, immune globulin (xembify), 100 mg, billed per 100 MG. The Medicare Part B ASP payment limit for October 2026 is $15.20 per billing unit, down 0.3% from July 2026. The practitioner MUE allows up to 480 units per date of service (MAI 3). Under OPPS it carries status indicator K in APC 9372. J1558 is billed in units of 100 MG; the quantity administered, the NDC package and the units on the claim must reconcile, which is the check that prevents CARC 16 and 151 returns on this line. The ASP crosswalk maps 4 NDCs to it, sold as Xembify by Grifols USA, LLC. 1 Medicare coverage article lists the code across 5 states, including .

Medicare Part B payment limit (ASP)

CMS sets the Part B payment limit for J1558 at $15.20 per 100 MG for October 2026, derived from manufacturer average sales price plus 6%, compared with $15.243 in July 2026. Beneficiary coinsurance is 20%.

ASP payment limits for J1558
QuarterPayment limitPerCoinsurance
October 2026$15.20100 MG20%
July 2026$15.243100 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 4 NDCs from 1 labeler to J1558. Report the NDC in the claim's drug segment and bill the number of J1558 units that equals the quantity administered divided by 100 MG; the last column gives units per full package.

NDCs that crosswalk to J1558
NDCDrug nameLabelerPackage sizeBilling units / package
13533-0810-05XembifyGrifols USA, LLC5 × 110
13533-0810-10XembifyGrifols USA, LLC10 × 120
13533-0810-20XembifyGrifols USA, LLC20 × 140
13533-0810-50XembifyGrifols USA, LLC50 × 1100

Medically Unlikely Edits (MUE)

CMS publishes 3 MUE values for J1558. For practitioners the limit is 480 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 J1558 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services4803 Date of Service Edit: ClinicalPrescribing Information
Facility outpatient hospital4803 Date of Service Edit: ClinicalPrescribing Information
DME supplier15003 Date of Service Edit: ClinicalClinical: CMS Workgroup

NCCI edits and add-on relationships

No active practitioner PTP pair lists J1558 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.

J1558 is neither an add-on code nor a designated primary code in the 2026 Q4 NCCI add-on edit file.

Medicare coverage articles

1 current Medicare Administrative Contractor article lists J1558 in their HCPCS tables, covering 5 states. Each article carries the covered and non-covered ICD-10 codes that medical-necessity denials (CARC 50) are adjudicated against.

Billing and Coding Articles listing J1558
ArticleTitleContractor(s)StatesRelated LCD
Billing and Coding: Immune GlobulinNovitas Solutions, Inc.DC DE MD NJ PAL35093

Hospital outpatient (OPPS) status

In the July 2026 OPPS Addendum B, J1558 carries status indicator K and is assigned to APC 9372, with a published national unadjusted payment of $15.24. Status K means the drug is paid separately under OPPS at the ASP-based rate rather than packaged into the procedure.

Common denials for J1558 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 J1558 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.

Explore QuickCodeExplore QuickRCMBook a demo

Frequently asked questions — HCPCS J1558

What does HCPCS code J1558 describe?

J1558 is defined by CMS as "Injection, immune globulin (xembify), 100 mg". Each billing unit represents 100 MG, so the units reported on the claim must equal the dose administered divided by that unit.

What is the Medicare reimbursement for J1558 in October 2026?

The ASP-based payment limit is $15.20 per 100 MG, with 20% beneficiary coinsurance. Medicare Administrative Contractors apply this limit; commercial payers use their own fee schedules. The July 2026 limit was $15.243.

How many units of J1558 can be billed per day?

The practitioner Medically Unlikely Edit is 480 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 "Prescribing Information" as the rationale.

Which NDCs map to J1558?

The October 2026 ASP crosswalk lists 4 NDCs from 1 labeler: Xembify (Grifols USA, LLC). For example NDC 13533-0810-05 is a 5 package equal to 10 billing units. The crosswalk's billing-units-per-package figure converts each package into J1558 units.

Does J1558 have NCCI bundling edits?

No active practitioner PTP pairs list J1558 as a column-1 or column-2 code in the v323r0 release. Unit limits (MUE) and medical-necessity coverage rules still apply.

Which Medicare coverage articles mention J1558?

1 current Billing and Coding Article in the Medicare Coverage Database list J1558, covering 5 states: (Billing and Coding: Immune Globulin).

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.