Monoferric (ferric derisomaltose) — J1437

Monoferric and the IV iron class

Monoferric (ferric derisomaltose) bills under J1437, 10 mg per billing unit, from Pharmacosmos Therapeutics. It ships in three single-dose vial sizes and carries no heart-failure, pediatric or hemodialysis indication. Five other IV iron agents compete in the same drug class under their own HCPCS codes, and none of them is a biosimilar of Monoferric or of each other.

Monoferric carries no boxed warning. The label's own warnings are hypersensitivity — monitor for at least 30 minutes after the infusion, with personnel and treatment for anaphylaxis immediately available — and iron overload, meaning the drug should not be given to a patient whose iron stores are already elevated. Neither warning resembles Injectafer's boxed warning for hypophosphatemia, and this label carries no phosphate-monitoring requirement at all.

Vials and NDCs

Three sizes cover the entire label without the split-vial arithmetic a drug with more sizes needs. At 50 kg and over the 1,000 mg vial is the whole dose in one draw; under 50 kg the billing-units calculator draws the fewest vials that cover the weight-based amount, tied to least waste.

Choosing among these six is not something this page settles on clinical grounds. For Monoferric, the single-visit, single-vial trade against the 9-of-15 payer step edit decides the choice more than the per-mg rate does.

Monoferric dosing

Every regimen is one infusion, not a course: 1,000 mg at 50 kg and over, 20 mg/kg under 50 kg, repeated only if iron deficiency anemia recurs. There is no induction phase and no maintenance interval on this label.

The two doses on this label

Monoferric has no heart-failure regimen, no pediatric dose and no hemodialysis dose — unlike Injectafer's weight-by-hemoglobin table, body weight alone decides which of two numbers applies. The full table:

There is no heart-failure indication, no pediatric indication and no hemodialysis indication on this label. A repeat dose is given only if iron deficiency anemia recurs, and the label sets no interval for when that repeat can occur.

Pre-treatment documentation

• Document oral iron failure or intolerance before the infusion — 13 of the 15 payers in the Clearance corpus require it, with trial lengths that run from 14 days to three months depending on the payer.
• Document ferritin and transferrin saturation within the window the payer names; 7 of 15 payers set a ferritin threshold and 6 a TSAT threshold. No payer in the corpus asks for a serum phosphate level — that is Injectafer's label requirement, not a Monoferric coverage rule.
• Confirm body weight before choosing the regimen: 1,000 mg at 50 kg and over, 20 mg/kg under 50 kg. There is no maintenance interval, no heart-failure indication, no pediatric dose and no hemodialysis dose on this label.
• Monitor for hypersensitivity for at least 30 minutes after the infusion, with personnel and treatment for anaphylaxis immediately available, and confirm the patient is not iron-overloaded before dosing — the label's own warnings, not a payer's.

Need the units for a patient's dose? Convert dose to J1437 billing units →

Monoferric billing reference

HCPCS

J1437 bills 10 mg per unit — the inverse of Injectafer's 1 mg per unit. A 1,000 mg dose is 100 units; a 100 mg dose is 10 units. Under 50 kg, units are the weight-based dose rounded up to the nearest 10 mg, so a 905 mg dose bills 91 units.

NDC

Three package sizes, each its own NDC — see the vial table in Drug & products above. At the 1,000 mg reference dose the claim carries one NDC; under 50 kg the fewest-vial combination can span two sizes, and the encounter note should say which vials were actually opened.

Administration

Administration is fixed, not a choice: the label's only route is an intravenous infusion diluted in 100 to 500 mL of 0.9% sodium chloride and run over at least 20 minutes. Full code language is at CPT 96374–96376 and CPT 96365–96366.

Modifiers

JZ — required when no drug is discarded. JW — required for documented waste.

The 1,000 mg reference dose draws one whole vial with nothing left over, so JZ is the norm at 50 kg and over. The under-50 kg regimen is the routine source of waste on this drug — see the worked vial example in the billing-units calculator for the JW-vs-JZ choice.

Full unit, vial and modifier math for any dose: calculate Monoferric billing units →

Claim form

CMS-1500 / 837P field map for a separately payable J1437 claim.

Monoferric coverage

The Clearance corpus carries 15 payers and 122 rules for ferric derisomaltose. 9 of those 15 payers require documented failure of another IV iron product before they cover Monoferric — a real step edit despite this being a single-visit infusion. The other 6 gate on oral iron failure and lab thresholds only.

• 13 of 15 commercial payer policy sets require prior authorization; 2 do not say clearly, so confirm those on the call
• 13 of 15 payers require documented oral iron failure or intolerance before ferric derisomaltose is covered.
• 7 of 15 payers set a ferritin threshold and 6 a TSAT threshold in their prerequisite rules; no payer asks for a serum phosphate level — this label carries no hypophosphatemia warning to check against.
• 12 rules set a quantity limit, 4 require reauthorization and 1 rule carries site-of-care language across the IV-iron class.

ICD-10-CM by indication

Checked against the NLM Clinical Table Search Service on 2026-09-19. Chart documentation decides which subtype applies, the same way it decides the 50 kg line between the two labeled doses.

Check the patient’s actual policy: See Monoferric coverage by payer →

Monoferric cost & financial access

Medicare ASP+6%: $21.877 / 10 mg · $2,187.70 / 1,000 mg. Administration (96365) allows $67.14 more, so the reference claim — a 1,000 mg dose plus 96365 — allows $2,254.84 total.

Under 50 kg, the weight-based dose changes the total: a 45 kg patient needs 900 mg (90 units), which allows $1,968.93 for the drug plus $67.14 for 96365, or $2,036.07 total.

At 20% coinsurance with the $283 Part B deductible already met, the patient owes $450.97 of the 1,000 mg reference claim, or $407.21 of the 45 kg example above. Commercial plans pay a contracted rate that varies by payer and state; 37 of 37 payer price files in this site's data carry a J1437 rate, and Aetna's all-states median runs $23.00 per 10 mg unit ($2.30/mg).

Per 1,000 mg of iron, Monoferric costs about 9.3× Venofer and 1.9× Injectafer — see the IV iron class table above. The same 1,000 mg of iron in the same single visit costs $1,096.10 more than Injectafer's single-dose alternative ($2,254.84 against $1,158.74), and far more than Venofer's course, which totals $412.70 over five visits. What the premium buys is the only full 1,000 mg dose that is one vial and one 20-minute infusion — no push, no second visit, and no weight math above 50 kg.

Patient cost

What a patient owes works out to the payer's allowed rate minus any benefits adjustment minus assistance applied. Confirm which weight band the encounter reflects before estimating — the 50 kg cutoff changes the dose, the units and the allowed amount together.

Calculate a Monoferric patient estimate →

Copay & financial assistance

The Monoferric Patient Solutions Copay Assistance Program pays a commercially insured patient's cost down to $0 per dose, up to $2,000 per treatment and $4,000 a calendar year — but it pays only the drug, never the infusion or the office visit, and it excludes Medicare, Medicaid and any government plan.

The separate Monoferric Patient Solutions Patient Assistance program ships the drug free to the provider for uninsured patients at or under 300% of the federal poverty level, with no stated cap.

See current Monoferric assistance programs →

Common Monoferric errors & fixes