CareCost Vials
2 × 500 mg
1 billing unit = 1 mg
800 mg dose → 800 billing units
J0174 · lecanemab-irmb
500 mg and 200 mg single-dose vials · JW/JZ waste rules may apply
Calculate this patient's units ↓Typical Leqembi dose: 10 mg/kg
This Leqembi claim carries straight into Claim Check.
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Patient owes, 800 mg
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36 payer price files · Commercial + Medicare · Copay and foundation status · Deductible, coinsurance and out-of-pocket math
Leqembi J0174 is billed in units of 1 mg: weight (kg) × 10 mg/kg = dose in mg = billing units. Example: 80 kg × 10 mg/kg = 800 mg = 800 billing units.
Leqembi ships in two vial sizes, 500 mg and 200 mg, and the units drawn from the vial can exceed the units administered. The rule the page applies is the fewest vials that cover the dose, and among draws that use the same number of vials, the one that discards the least drug. Report any leftover as JW on its own claim line, and use JZ only when nothing was discarded.
Medicare pays $1.361 per billing unit (ASP+6%, per mg), effective for claims in Q4 2026
— $1,088.80 for the 800-unit example above, plus $272.20 for the 200 discarded units if the payer
reimburses waste.
Each row applies the same rule: the fewest vials that cover the dose, and among draws that use the same number of vials, the one that discards the least drug.
| Weight | Dose | Vials drawn | Discarded | Modifier |
|---|---|---|---|---|
| 50 kg | 500 mg | 1 × 500 mg | 0 mg | JZ |
| 60 kg | 600 mg | 500 + 200 mg | 100 mg | JW |
| 70 kg | 700 mg | 500 + 200 mg | 0 mg | JZ |
| 80 kg | 800 mg | 2 × 500 mg | 200 mg | JW |
| 90 kg | 900 mg | 2 × 500 mg | 100 mg | JW |
| 100 kg | 1,000 mg | 2 × 500 mg | 0 mg | JZ |
The 80 kg row draws two 500 mg vials rather than one 500 mg and two 200 mg vials; the two-vial draw wastes more (200 mg against 100 mg), but the fewest-vials rule takes it anyway because it opens one fewer vial.
JZ — no discarded drug from a single-dose container. JW — discarded drug from a single-dose container, reported on its own claim line.
J0174 × 700 JZ · 96365 × 1.
J0174 × 800 · J0174 × 200 JW · 96365 × 1.
96365 covers the initial hour of a therapeutic, prophylactic or diagnostic infusion. A Leqembi infusion runs about one hour, so the claim reports 96365 × 1 alone. 96366 (each additional hour) applies only when the infusion runs more than 30 minutes past the first hour. 96413 and 96415 are the chemotherapy administration codes and are the wrong family for an anti-amyloid antibody.
Leqembi is supplied as a ready-to-dilute solution, 100 mg/mL, in two single-dose vial sizes: 500 mg/5 mL (NDC 62856-215-01) and 200 mg/2 mL (NDC 62856-212-01). There is no lyophilized powder to reconstitute; the ordered dose is withdrawn and diluted into the infusion bag. A subcutaneous product, LEQEMBI IQLIK, is also on the label as a patient-administered autoinjector; it is not a J0174 office claim. See the FDA Leqembi label (BLA761269) for the full dilution and administration instructions.
J0174 is the HCPCS code for Leqembi (lecanemab-irmb); there is no biosimilar for this molecule, so J0174 is the only code the IV product bills under. Kisunla (donanemab-azbt), the other anti-amyloid antibody, bills separately under J0175 and is not interchangeable with Leqembi. See the HCPCS hub for coding across the full family. The Medicare rate for every quarter is on the cost page →
800 billing units. Leqembi J0174 bills 1 unit per mg, and the starting dose is 10 mg/kg, so 80 kg × 10 mg/kg = 800 mg = 800 units.
Two 500 mg vials. Leqembi ships in 500 mg and 200 mg single-dose vials, and the fewest-vials rule draws two 500 mg vials (1,000 mg) rather than one 500 mg plus two 200 mg vials, even though the second combination wastes less. The 200 mg left in the vials after the 800 mg dose is administered is reported on its own JW line.
Either, depending on the draw. A dose that lands on an exact multiple of the vials opened, such as 700 mg from a 500 mg and a 200 mg vial, bills JZ. A dose that leaves drug in the vial, such as 800 mg from two 500 mg vials, bills the leftover on a JW line.
96365. Leqembi is a therapeutic, prophylactic and diagnostic infusion, not a chemotherapy administration, so it bills 96365 (initial hour) alone for the roughly one-hour infusion. 96413 and 96415 are the chemotherapy administration codes and are the wrong family for an anti-amyloid antibody.
10 mg/kg by IV infusion every 2 weeks for the starting regimen, with the option to move to every 4 weeks after 18 months. An 80 kg patient is dosed at 800 mg regardless of which interval is in use.
$1.361 per billing unit (ASP+6%, per mg), effective for claims in Q4 2026 — $1,088.80 for an 800 mg dose.
Data current: pricing Q4 2026 · payer policies Aug 2026
Sources: CMS ASP pricing files (Q4 2026); FDA-approved prescribing information (LEQEMBI label, revised July 2026, BLA761269); CMS single-dose container JW/JZ policy (effective July 1, 2023); 20 commercial payer medical policies (Clearance corpus); CPT codebook administration-code guidance.
Reviewed September 20, 2026 by Erin Rose, CareCost Estimate founder. Methodology →