Skip to main content
HCPCS J1643 · Level II · Part B drug

HCPCS J1643: Injection, heparin sodium (pfizer), not therapeutically equivalent to j1644,

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 J1643

Billing unit
1000 UNITS
Inj heparin, pfizer, 1000u
ASP payment limit
$2.248
October 2026; +31.4% vs July 2026
Practitioner MUE
40
MAI 3
OPPS status
SI N
NCCI exposure
no PTP pairs
Coverage articles
0
none list this code

TL;DR

HCPCS J1643 is the Level II code for Injection, heparin sodium (pfizer), not therapeutically equivalent to j1644,, billed per 1000 UNITS. The Medicare Part B ASP payment limit for October 2026 is $2.248 per billing unit, up 31.4% from July 2026. The practitioner MUE allows up to 40 units per date of service (MAI 3). Under OPPS it carries status indicator N. J1643 is billed in units of 1000 UNITS; 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 1 NDC to it, sold as Heparin Sodium (Porcine) by Pfizer Inc. No current Billing and Coding Article lists J1643, 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 J1643 at $2.248 per 1000 UNITS for October 2026, derived from manufacturer average sales price plus 6%, compared with $1.711 in July 2026. Beneficiary coinsurance is 20%.

ASP payment limits for J1643
QuarterPayment limitPerCoinsurance
October 2026$2.2481000 UNITS20%
July 2026$1.7111000 UNITS—
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 J1643. Report the NDC in the claim's drug segment and bill the number of J1643 units that equals the quantity administered divided by 1000 UNITS; the last column gives units per full package.

NDCs that crosswalk to J1643
NDCDrug nameLabelerPackage sizeBilling units / package
00069-0043-01Heparin Sodium (Porcine)Pfizer Inc2 × 2550

Medically Unlikely Edits (MUE)

CMS publishes 2 MUE values for J1643. For practitioners the limit is 40 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 J1643 by setting
SettingMUE (units/DOS)MAICMS rationale
Practitioner services403 Date of Service Edit: ClinicalPrescribing Information
Facility outpatient hospital403 Date of Service Edit: ClinicalPrescribing Information

NCCI edits and add-on relationships

No active practitioner PTP pair lists J1643 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.

J1643 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 J1643 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, J1643 carries status indicator N. Status N means payment is packaged into the associated procedure and no separate OPPS payment is made.

Common denials for J1643 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 J1643 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 J1643

What does HCPCS code J1643 describe?

J1643 is defined by CMS as "Injection, heparin sodium (pfizer), not therapeutically equivalent to j1644,". Each billing unit represents 1000 UNITS, so the units reported on the claim must equal the dose administered divided by that unit.

What is the Medicare reimbursement for J1643 in October 2026?

The ASP-based payment limit is $2.248 per 1000 UNITS, with 20% beneficiary coinsurance. Medicare Administrative Contractors apply this limit; commercial payers use their own fee schedules. The July 2026 limit was $1.711.

How many units of J1643 can be billed per day?

The practitioner Medically Unlikely Edit is 40 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 J1643?

The October 2026 ASP crosswalk lists 1 NDC from 1 labeler: Heparin Sodium (Porcine) (Pfizer Inc). For example NDC 00069-0043-01 is a 2 package equal to 50 billing units. The crosswalk's billing-units-per-package figure converts each package into J1643 units.

Does J1643 have NCCI bundling edits?

No active practitioner PTP pairs list J1643 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.