The CPT code for Injectafer (ferric carboxymaltose) is 96374 for the labeled way most doses are given — undiluted, as a slow IV push at about 100 mg per minute, which finishes a 750 mg dose in roughly 7–8 minutes — and 96365 only when the dose is diluted and the infusion is documented at more than 15 minutes, since CPT reports 15 minutes or less as a push regardless of dilution. The drug bills J1439 at 1 mg per unit, so 750 mg is 750 units and 1,000 mg is 1,000 units. A full course is two doses at least seven days apart (or a single 15 mg/kg dose, up to 1,000 mg, for a patient 50 kg or over) — each dose is its own date of service, with its own administration code and its own J1439 line, never combined onto one claim.
Injectafer’s FDA label gives two ways to give the same dose: undiluted, injected directly at a rate of approximately 100 mg per minute, or diluted in up to 250 mL of 0.9% sodium chloride and infused over at least 15 minutes. CMS defines the line between a push and an infusion by documented time, not by whether the drug was diluted:
“For chemotherapy administration and therapeutic, prophylactic and diagnostic injections and infusions, an intravenous or intra-arterial push is defined as: 1.) an injection in which the healthcare professional is continuously present to administer the substance/drug and observe the patient; or 2.) an infusion of 15 minutes or less.” — CMS Pub. 100-04 Ch. 12 §30.5
MAC guidance treats an IV line charted with no start and stop times the same way, as a push, on the reasoning that nothing in the record supports an infusion — but that documentation rule is not in Chapter 12 itself. It is administrative practice layered on top of the CMS time definition, and at least one MAC (Palmetto GBA, Article A53778) accepts a stop time calculated from the volume, start time and infusion rate in place of a charted clock reading.
Run the undiluted 750 mg dose at 100 mg/min and it is over in about 7.5 minutes — a push, 96374, and the primary code for this drug. The label gives the 1,000 mg single dose its own instruction: administer as a slow intravenous push over 15 minutes — the outer edge of the push definition, and still 96374. Diluting the drug does not, by itself, change anything: a diluted dose infused over exactly 15 minutes is still 15-minutes-or-less and still 96374. Only a diluted infusion documented at 16 minutes or more earns 96365, and each additional hour beyond the first, if the infusion actually runs that long, is 96366. 96413 (chemotherapy infusion) never applies — ferric carboxymaltose is not an antineoplastic.
The chart note is what decides a review, not the order or the vial label. “Diluted in 100 mL NS” with no start and stop times, or with times 15 minutes apart or less, supports 96374. Only explicit start and stop times spanning 16 minutes or more support 96365 — and that documentation burden is one reason 96374 is the code seen on the large majority of Injectafer claims.
J1439’s descriptor is per 1 mg, so the unit count is simply the milligram dose: 750 mg is 750 units, 1,000 mg is 1,000 units, and a 40 kg pediatric dose at 15 mg/kg (600 mg) is 600 units. The label sets the regimen as a course, not a repeating interval — for a patient 50 kg or over with iron-deficiency anemia, that is two 750 mg doses at least 7 days apart (1,500 mg total), or a single alternative of 15 mg/kg up to 1,000 mg. Patients under 50 kg (including children 1 year and up) get 15 mg/kg per dose, two doses at least 7 days apart.
Each dose in the two-dose regimen is its own encounter: its own date of service, its own administration line (96374 or 96365, coded independently on each date’s own documented time), and its own J1439 line. That is the direct answer to a two-dose course billed “at different intervals via IVP” — there is no single claim that carries both doses. Dose one: J1439 × 750 plus 96374 on date one. Dose two, seven or more days later: J1439 × 750 plus 96374 again, on its own claim with its own date of service. The MUE for J1439 is 1,000 units per date of service, at MAI 3 (a Date of Service Edit that documentation can support past the edit) — which is exactly the 1,000 mg single-dose ceiling, so no single legitimate Injectafer dose exceeds it, but two 750 mg doses billed on the same date of service would.
Injectafer ships in four single-dose vials: 100 mg/2 mL, 500 mg/10 mL, 750 mg/15 mL and 1,000 mg/20 mL. JZ and JW attach to whichever vial or vials were actually opened, not to the dose in the abstract:
The billing-units math always draws the fewest vials that cover the dose; a 750 mg dose should come from the 750 mg vial whenever one is stocked, which is the only way to keep the standard course a zero-waste, JZ-only claim. Every Medicare Part B single-dose-container line has required JW or JZ since July 1, 2023 — a line with neither, or with both, rejects.
Injectafer’s two FDA indications carry different ICD-10 families and, for heart failure, a documentation trap. Iron-deficiency anemia bills D50.0, D50.8 or D50.9 (the bare D50 category code is not billable); non-dialysis CKD anemia bills D63.1 paired with the N18 stage. The heart-failure indication (approved 2023, NYHA class II/III, to improve exercise capacity) bills E61.1 (iron deficiency) paired with any billable I50 code — I50.1, I50.20-I50.23, I50.30-I50.33, I50.40-I50.43, I50.810-I50.89 or I50.9. The bare I50.2, I50.3 and I50.4 are category codes and will not process; the chart has to support the specific fourth or fifth character before the claim goes out. Neither indication changes the administration or HCPCS coding above — only the diagnosis and, for heart failure, the label’s own weight-and-hemoglobin dosing table govern the dose given.
Both claims price out through the Code this visit tool; the units and JW/JZ math for any dose and any of the four vial sizes is in the units calculator.
Each dose is its own claim: J1439 at the mg dose given (750 units for a 750 mg dose) plus 96374 for the push, on that date of service. The second dose, at least 7 days later, repeats the same pair of lines on its own date — there is no combined claim covering both doses.
96374 for the labeled undiluted IV push (documented at 15 minutes or less), which covers the large majority of Injectafer doses. 96365 applies only when the dose is diluted and the infusion is documented at more than 15 minutes; dilution alone does not qualify a dose for 96365.
750 units — J1439 bills 1 mg per unit. A 1,000 mg single dose is 1,000 units, at the MUE ceiling for the code. Whether the line carries JZ or JW depends on which vial size was opened to reach that dose.
The administration and HCPCS coding are the same either way. The diagnosis differs: heart failure bills E61.1 paired with a billable I50 child code (e.g., I50.23), and the dose is set by the label's weight-and-hemoglobin table rather than a flat 750 mg. Iron-deficiency anemia bills D50.0, D50.8 or D50.9.
Quoted passages are reproduced from the cited federal publications; everything else is our reading of them. The methodology by which we resolve source disagreements is described in the Methodology.