J1643 — Injection, heparin sodium (pfizer), not therapeutically equivalent to j1644, per 1000 units
J1643 is a HCPCS Level II code for injection, heparin sodium (pfizer), not therapeutically equivalent to j1644, per 1000 units. It belongs to the Drugs Administered Other Than Oral Method section. Whether Medicare pays it depends on the coverage rule below.
Medicare coverage: Special coverage instructions apply
There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.
From the coverage field of the CMS Alpha-Numeric HCPCS File, release 2026Q3-Jul. This states Medicare’s position on the code, not on your particular claim.
Physician fee schedule statusE
Excluded from the physician fee schedule by regulation. Payment, where it exists, comes from another fee schedule (drugs via ASP, supplies via DMEPOS, and so on).
Global period: XXX
Want the dollar amount for your locality? The fee calculator applies your GPCI and the current conversion factor.
Medically Unlikely Edits — units per day
The most units of J1643 Medicare will pay on one date of service. Bill more on a single line and it is denied. The limit is not the same in every setting, so the row that matters is the one matching the claim you are building.
- practitioner
- 40 units MAI 3 — Date of Service Edit: Clinical · Prescribing Information
- outpatient
- 40 units MAI 3 — Date of Service Edit: Clinical · Prescribing Information
The adjudication indicator decides whether exceeding the limit is worth appealing at all: MAI 1 is a line edit you can support with documentation, MAI 3 is a date-of-service edit that is also appealable, and MAI 2 is absolute — no documentation overrides it. CMS MUE 2026Q3.
The CMS record for J1643
- Long descriptor
- Injection, heparin sodium (pfizer), not therapeutically equivalent to j1644, per 1000 units
- Short descriptor
- Inj heparin, pfizer, 1000u
- Added
- January 1, 2023
- BETOS
- O1E
- Pricing indicator
- 51 — Other
The official wording. This is what the code means.
CMS's 28-character form, which is what shows up on a remittance advice.
When CMS introduced the code.
Berenson-Eggers Type of Service — CMS's own analytic grouping.
Drugs.
Codes adjacent to J1643
HCPCS has no hierarchy — related items simply sit next to each other in the numbering. If J1643 is not quite right, the correct code is very often within a few positions of it.
- J1626Injection, granisetron hydrochloride, 100 mcg
- J1627Injection, granisetron, extended-release, 0.1 mg
- J1628Injection, guselkumab, 1 mg
- J1630Injection, haloperidol, up to 5 mg
- J1631Injection, haloperidol decanoate, per 50 mg
- J1632Injection, brexanolone, 1 mg
- J1640Injection, hemin, 1 mg
- J1642Injection, heparin sodium, (heparin lock flush), per 10 units
- J1644Injection, heparin sodium, per 1000 units
- J1645Injection, dalteparin sodium, per 2500 iu
- J1650Injection, enoxaparin sodium, 10 mg
- J1652Injection, fondaparinux sodium, 0.5 mg
- J1655Injection, tinzaparin sodium, 1000 iuterminated
- J1670Injection, tetanus immune globulin, human, up to 250 units
- J1675Injection, histrelin acetate, 10 micrograms
- J1700Injection, hydrocortisone acetate, up to 25 mg
Questions about J1643
What is HCPCS code J1643?
J1643 is a HCPCS Level II code for injection, heparin sodium (pfizer), not therapeutically equivalent to j1644, per 1000 units. It sits in the Drugs Administered Other Than Oral Method section.
Does Medicare cover J1643?
The CMS HCPCS file marks J1643 as "Special coverage instructions apply". There are published conditions attached to this code. Check the applicable coverage policy before billing it: the code being valid is not the same as the service being covered.
How is J1643 paid under the physician fee schedule?
J1643 carries PFS status code E. Excluded from the physician fee schedule by regulation. Payment, where it exists, comes from another fee schedule (drugs via ASP, supplies via DMEPOS, and so on).