CareCost Vials
1 × 1,000 mg
1 billing unit = 10 mg
1,000 mg dose → 100 billing units
J1437 · ferric derisomaltose
100 mg / 500 mg / 1,000 mg single-dose vials · JZ when nothing is discarded
Calculate this patient's units ↓1,000 mg single infusion, 50 kg and over · 20 mg/kg under 50 kg · non-dialysis CKD dosed the same
Monoferric · 200 billing units carry straight into the claim.
Claim Check builds the whole visit — J1437 units, the administration line, the modifiers and the Medicare allowed amount — and prices it against your payer's rate. The estimate turns the same visit into what the patient owes.
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Patient owes, 1000 mg
Change the payer and the estimate re-prices against that payer's own published rate. The result is a good faith estimate for the patient.
J1437 bills 10 mg per unit: ordered dose ÷ 10 mg = billing units. A 500 mg dose is 50 units, a 100 mg dose is 10 units, and the labeled 1,000 mg dose is 100 units — the inverse of the Injectafer trap, where billing by the vial instead of the milligram under-bills. Weight-based doses under 50 kg round up to the nearest whole unit: a 905 mg dose is 90.5 mg ÷ 10, which rounds up to 91 units.
Monoferric ships in three single-dose vial sizes — 100 mg, 500 mg and 1,000 mg — and the calculator draws the fewest vials that cover the ordered dose, breaking any tie toward the least amount left over. The 1,000 mg dose at 50 kg and over always draws one 1,000 mg vial, so JZ is the modifier. Under 50 kg, 20 mg/kg rarely lands on a vial size exactly — a 45 kg patient's 900 mg dose still draws one 1,000 mg vial, but 100 mg is discarded on a JW line.
The alternative that wastes nothing, one 500 mg vial plus four 100 mg vials, opens five vials instead of one, so the fewest-vials rule skips it.
Medicare pays $21.077 per 10 mg billing unit (ASP+6%), effective for claims in Q3 2026 —
$2,107.70 for the 1,000 mg example above, before the $67.14 administration allowance.
| Dose | Billing units | Vials | Modifier | Note |
|---|---|---|---|---|
| 1,000 mg (IDA / non-dialysis CKD, 50 kg and over) | 100 | 1 × 1,000 mg | JZ | The labeled dose and the reference patient on every page |
| 500 mg (e.g., 25 kg patient at 20 mg/kg) | 50 | 1 × 500 mg | JZ | Matches a vial size exactly, nothing discarded |
| 900 mg (45 kg patient at 20 mg/kg) | 90 + 10 JW | 1 × 1,000 mg | JW | 100 mg discarded; 500 mg + 4 × 100 mg wastes nothing but opens five vials |
| 905 mg (rounding example) | 91 + 9 JW | 1 × 1,000 mg | JW | 90.5 units rounds up to 91; the rest of the vial is JW |
| 100 mg (smallest vial) | 10 | 1 × 100 mg | JZ | Smallest available vial, nothing discarded |
JZ — no discarded drug from a single-dose container. JW — discarded drug from a single-dose container, reported on its own claim line. One of the two is required on every J1437 claim per CMS's July 1, 2023 single-dose container policy.
J1437 × 100 JZ · 96365 × 1. Non-dialysis CKD is dosed the same way —
1,000 mg at 50 kg and over, one 1,000 mg vial, JZ.
J1437 × 90 · J1437 × 10 JW.
A pharmacy that instead draws one 500 mg vial plus four 100 mg vials delivers the same 900 mg with nothing
left over — but that combination opens five vials, which is why the fewest-vials rule picks the
1,000 mg vial and the JW line instead.
96365 is the only administration code this drug uses. The label's only route is an intravenous infusion, diluted in 100 to 500 mL of 0.9% sodium chloride at more than 1 mg iron per mL, run over at least 20 minutes. There is no push route on this label, so 96374 does not apply here — the opposite of Injectafer, whose label doses by IV push.
At 20 minutes the infusion never reaches the 96366 each-additional-hour line, and Monoferric has no additional administration code at any dose — the manifest carries none. The CPT 96365–96366 and CPT 96374–96376 pages carry the full definitions; this page only confirms which code a Monoferric infusion uses.
Monoferric ships in three single-dose vial sizes — 100 mg/1 mL (NDC 73594-9301-2),
500 mg/5 mL (73594-9305-1) and 1,000 mg/10 mL (73594-9310-1) — the same
multi-vial draw Injectafer introduced, one size fewer. J1437 (“Injection, ferric derisomaltose,
10 mg”) covers ferric derisomaltose from any manufacturer; Pharmacosmos Therapeutics's Monoferric is the
reference product billed under that code. Five other IV iron agents — Injectafer, Ferrlecit, Feraheme,
INFeD and Venofer — are a different molecule each, with their own HCPCS codes and their own unit math;
none of them bills under J1437.
See the FDA Monoferric label for full dosing and administration instructions, or the current Medicare rate for J1437 →.
100 billing units. Monoferric J1437 bills 1 unit per 10 mg, so divide the dose in mg by 10 to get the unit count.
It depends on weight: 20 mg/kg, rounded up to the nearest whole unit. A 45 kg patient's 900 mg dose is 90 units, drawn from one 1,000 mg vial with 100 mg (10 units) discarded on a JW line — or one 500 mg vial plus four 100 mg vials, which leaves nothing to discard but opens five vials instead of one.
J1437. It covers ferric derisomaltose from any manufacturer, and Pharmacosmos Therapeutics's Monoferric is the reference product billed under that code.
JZ on the 1,000 mg dose at 50 kg and over — it matches the 1,000 mg vial exactly with nothing left over. Under 50 kg, 20 mg/kg rarely lands on a vial size exactly; a 45 kg patient's 900 mg dose still draws one 1,000 mg vial and discards 100 mg on a JW line.
Billing 1,000 units for a 1,000 mg dose, as if J1437 paid 1 unit per mg like Injectafer's J1439. J1437 is 10 mg per unit, so a 1,000 mg dose is 100 units — billing 1,000 units instead pays $21,077.00 rather than $2,107.70.
Data current: pricing Q3 2026 · payer policies Aug 2026
Sources: CMS ASP pricing files (Q3 2026); CMS physician fee schedule; FDA-approved prescribing information (MONOFERRIC label, Pharmacosmos Therapeutics, published December 10, 2025); CMS single-dose container JW/JZ policy (effective July 1, 2023); CPT codebook administration-code guidance.
Reviewed September 19, 2026 by Erin Rose, CareCost Estimate founder. Methodology →