HCPCS
J0174
1 billing unit = 1 mg
No MUE on file for J0174
Leqembi and the anti-amyloid antibody family
Two anti-amyloid antibodies are approved for early symptomatic Alzheimer's disease (mild cognitive impairment or mild dementia, with amyloid confirmed by PET or CSF): Leqembi and Kisunla. Both are IV infusions billed with 96365, never 96413. ASP comparison lives in Current Leqembi pricing.
| Brand | HCPCS | Manufacturer | Generic |
|---|---|---|---|
| Leqembi (this page) | J0174 | Eisai / Biogen | lecanemab-irmb |
| Kisunla | J0175 | Eli Lilly | donanemab-azbt |
Leqembi and Kisunla are not interchangeable, and a payer may require one before the other. Leqembi's own commercial corpus asks for a prior anti-amyloid antibody trial in only 1 of 20 payers: BCBS MA, whose policy requires that the patient has "not currently receiving and has not previously received another anti-amyloid monoclonal antibody."
Both drugs carry the boxed warning for amyloid related imaging abnormalities (ARIA) with scheduled MRIs, and Medicare pays both under NCD 200.3, coverage with evidence development. Leqembi's dose, vial sizes and administration coding are covered in full below; see Leqembi dosing.
Leqembi dosing
Weight-based at 10 mg/kg by IV infusion over about one hour: 800 mg for an 80 kg patient, drawn from 500 mg and 200 mg vials.
Boxed warning: amyloid related imaging abnormalities (ARIA). Monoclonal antibodies directed against aggregated forms of beta amyloid, including LEQEMBI, can cause ARIA, characterized as ARIA with edema (ARIA-E) and ARIA with hemosiderin deposition (ARIA-H). ARIA usually occurs early in treatment and is usually asymptomatic.
| Population | Regimen | Notes |
|---|---|---|
| Starting regimen (first 18 months) | 10 mg/kg IV over about one hour, every 2 weeks | For an 80 kg patient that is 800 mg: the fewest-vials draw is two 500 mg vials (1,000 mg), so 200 mg is reported on a JW line; a 200 mg vial exists but the mixer only reaches for it when it lowers the vial count. Confirmed amyloid pathology, APOE ε4 genotyping and a baseline MRI precede the first infusion; MRIs follow at months 1, 2, 3 and 6. |
| Maintenance (after 18 months) | 10 mg/kg IV over about one hour, every 4 weeks (or continue every 2 weeks) | Same dose, half the visits. The first maintenance infusion comes 2 weeks after the last starting-regimen infusion. The label also offers a subcutaneous maintenance route, LEQEMBI IQLIK 360 mg once a week by autoinjector, which the patient self-administers; that product is not billed as J0174 in the office. |
Pretreatment workup and MRI schedule
Before the first infusion: confirm amyloid pathology by PET or CSF, obtain ApoE ε4 genotyping, and get a baseline brain MRI. Follow-up MRIs are scheduled at months 1, 2, 3 and 6 of treatment; the label bases ARIA treatment decisions on the type, severity and presence of symptoms found at each scan.
18-month transition
The starting regimen runs at 10 mg/kg IV every 2 weeks. After 18 months, the prescriber may continue that schedule or move to IV maintenance every 4 weeks at the same dose; the first maintenance infusion follows 2 weeks after the last starting-regimen dose.
Subcutaneous LEQEMBI IQLIK
The label also offers a subcutaneous maintenance option, LEQEMBI IQLIK (500 mg weekly starting, 360 mg weekly maintenance), delivered by an autoinjector the patient self-administers at home. It is not an office-administered infusion, so it is not a J0174 claim.
Need the billing units for a patient? Convert dose to J0174 billing units →
Leqembi billing reference
HCPCS
J0174: 1 mg per billing unit. No MUE is on file for J0174.
NDCs
Two vial sizes, Eisai labeler 62856. Pad to 11 digits with a leading zero in the 3-digit product segment for CMS-1500 Box 24A.
| NDC (10-digit) | NDC (11-digit, claim form) | Package |
|---|---|---|
62856-215-01 | 62856-0215-01 | 500 mg/5 mL single-dose vial |
62856-212-01 | 62856-0212-01 | 200 mg/2 mL single-dose vial |
11-digit NDC required on most claim forms. Use the
N4 qualifier in CMS-1500 Box 24A shaded area with unit of measure and quantity actually drawn from the vial.
Administration
Leqembi's roughly one-hour infusion is billed with 96365 alone. 96413 and 96415, CPT's chemotherapy administration codes, are the wrong family for a non-oncology monoclonal antibody.
| CPT | Description | Use for |
|---|---|---|
96365 | Intravenous infusion, for therapy, prophylaxis or diagnosis; initial, up to 1 hour | The Leqembi infusion ($67.14, Medicare PFS national non-facility, 2026) |
96366 | Intravenous infusion, for therapy, prophylaxis or diagnosis; each additional hour | Only when the infusion runs more than 30 minutes past the first hour, past 90 minutes total ($21.38, Medicare PFS national non-facility, 2026) |
96413 | Chemotherapy administration, IV infusion technique; up to 1 hour | Wrong family for Leqembi: reserved for chemotherapy, not a non-oncology monoclonal antibody |
Modifiers
JZ: required when no drug is discarded. JW: required for documented waste of unused single-dose-vial drug. The mixer draws the fewest vials that cover the dose, even when that combination wastes more than an alternative would.
Effective July 1, 2023, CMS requires JZ on every single-dose container claim with no waste, and JW on a separate line for documented waste. For 800 mg (an 80 kg patient), the fewest-vials draw takes two 500 mg vials (1,000 mg total): a 500 mg + 200 mg + 200 mg draw would waste only 100 mg, but it takes three vials, so the mixer does not choose it. The 800 mg administered line carries no waste modifier, and a second J0174 line for the 200 mg discarded carries JW.
| Weight | Dose | Vial draw | Administered | Waste / modifier |
|---|---|---|---|---|
| 60 kg | 600 mg | 500 mg + 200 mg (2 vials) | 600 mg | 100 mg, JW |
| 80 kg | 800 mg | 500 mg + 500 mg (2 vials) | 800 mg | 200 mg, JW |
| 100 kg | 1,000 mg | 500 mg + 500 mg (2 vials) | 1,000 mg | None, JZ |
Claim form
CMS-1500 / 837P (physician office, AIC; POS 11/49) field map for a J0174 claim.
| Information | CMS-1500 box | Notes |
|---|---|---|
| NDC qualifier + 11-digit NDC + UoM + qty | 24A shaded area | Format: N4 qualifier + 11-digit NDC + UN + quantity drawn |
| HCPCS J0174 (administered; JZ only if no waste) | 24D (drug line) | Administered units, per MAC rounding |
| HCPCS J0174 + JW (when waste) | 24D (separate line) | Discarded units, per MAC rounding |
| Drug units | 24G | Administered + waste split across two lines, same DOS |
| CPT 96365 | 24D (admin line) | 1 unit for the initial hour; add 96366 only past 90 minutes |
| ICD-10 | 21 | G31.84 (MCI due to Alzheimer's) or G30.9 (mild Alzheimer's dementia) |
| NPI | 17b / 24J / 33a | Rendering and billing provider NPI |
| PA number (when required) | 23 | Required by most commercial payers in 2026 |
Leqembi coverage
- 20 of 21 commercial payer policy sets require prior authorization; 1 do not say clearly, so confirm those on the call
- Requirements vary by diagnosis, payer and site of care
- Amyloid pathology confirmed by PET or CSF, the MCI or mild dementia stage, and a baseline MRI are the recurring clinical prerequisites; the label requires ApoE ε4 genotyping before the first dose
- Medicare pays under NCD 200.3, coverage with evidence development: registry enrollment and the amyloid result are claim facts as much as clinical ones
- BCBS MA is the one payer in the 20-payer corpus that requires no prior anti-amyloid antibody before Leqembi
ICD-10 codes by indication
Two FDA-indicated diagnoses, each mapped to its own dxKey in the payer corpus.
| Indication | ICD-10 | Payers matching this dxKey |
|---|---|---|
| Mild cognitive impairment due to Alzheimer's disease | G31.84 | 19 of 20 |
| Mild Alzheimer's disease dementia | G30.9 | 20 of 20 |
Prior authorization and prerequisites
18 of 20 commercial payers require prior authorization. Rule mix across the 175-rule corpus: clinical prerequisite (83), covered indication (39), prior authorization (18), contraindication/exclusion (14), dosing (12), site of care (3), quantity limit (3), reauthorization (3).
Quantity limits, quoted verbatim: BCBS FL, "The dosage does not exceed 10 mg/kg IV every 14 days"; Capital Blue, "1200 billable units (1200 mg) every 14 days"; CareFirst, "Leqembi IQLIK will not be used within the initial 18 months of therapy."
Reauthorization, quoted verbatim: BCBS MA, "Length of Approval 12 months unless otherwise stated in criteria below"; Capital Blue, "Renewal: Prior authorization validity may be renewed every 12 months thereafter." BCBS SC requires the member to have been evaluated for ARIA on MRI before the fifth dose as part of its first reauthorization.
Site of care / POS
Payer site-of-care UM decides the infusion setting: office (POS 11), AIC (POS 49), or hospital outpatient (POS 22 on-campus, 19 off-campus).
| Setting | POS | Claim form | Electronic | Typical use |
|---|---|---|---|---|
| Physician office / infusion suite | 11 | CMS-1500 | 837P | Most maintenance doses |
| Ambulatory infusion center (AIC) | 49 | CMS-1500 | 837P | Maintenance post site-of-care steering |
| On-campus hospital outpatient | 22 | UB-04 / CMS-1450 | 837I | First dose, reaction history |
| Off-campus hospital outpatient | 19 | UB-04 / CMS-1450 | 837I | First dose at off-campus HOPD |
| Patient home | 12 | CMS-1500 | 837P | Home infusion permitted by some payers (verify) |
Check the patient's actual policy: See Leqembi coverage by payer →
Current Leqembi pricing
Medicare ASP+6%: $1.361 / 1 mg · $1,088.80 / 800 mg. Sequestration reduces Medicare's 80% share by 2% (effective ASP+4.3% overall). Commercial plans pay a contracted rate that differs by payer and state.
26 doses a year (10 mg/kg every 2 weeks, 800 mg at 80 kg) at $1,428.14 per infusion — drug (including the 200-unit JW line) plus 96365 administration — total $37,131.64 before the sequester. That is the full annual drug-plus-administration cost for a patient staying on schedule, before benefits or assistance.
The full Medicare-basis claim for an 80 kg patient: J0174 × 800 units $1,088.80, plus J0174-JW × 200 units $272.20, plus 96365 $67.14, total $1,428.14. The patient's 20% coinsurance, once the Part B deductible is met, is $285.63.
| Basis | Rate / mg | 800 mg total |
|---|---|---|
| Medicare ASP+6% (Q4 2026) | $1.361 | $1,088.80 |
| Aetna commercial median (36 of 36 payer files carry a rate) | $1.20 | $960.00 |
Look up commercial reimbursement →
Patient cost
The patient's actual responsibility depends on: payer allowed rate · benefits · − assistance · = patient responsibility.
Calculate a Leqembi patient estimate →
Copay & financial assistance
Commercial: LEQEMBI Copay Assistance covers drug cost only, patient pays $0 per infusion, up to $10,000 per calendar year, for eligible commercially insured patients. Uninsured: the LEQEMBI Patient Assistance Program (free drug), part of LEQEMBI Companion provides free drug, shipped directly to the provider, for patients at or below 300% of the federal poverty level.
Common Leqembi denials & fixes
| Denial reason | Common cause | Fix |
|---|---|---|
| Wrong admin code (96413 billed instead of 96365) | Biller defaulted to the chemotherapy administration family | Resubmit with 96365; add 96366 only if the infusion runs more than 90 minutes total. |
| JW line missing, or JW billed on a JZ draw | Discarded drug not reported as a separate line, or a no-waste 1,000 mg draw mistakenly carries a JW line | Report the discarded mg on a separate J0174 line with JW only when the vial draw exceeds the administered dose; use JZ when it does not. |
| Amyloid pathology not documented | PA submitted without a PET or CSF result confirming amyloid | Submit the amyloid biomarker report with the appeal. |
| ApoE genotyping not on file | Payer quotes ApoE ε4 genotyping as a prerequisite and the result is not in the chart | Order the genotype test and resubmit with the result. |
| Registry / CED enrollment not documented (Medicare) | Patient not enrolled in a CMS-approved registry, or the enrollment ID is missing from the claim | Enroll in a CMS-approved registry (NACC's Alzheimer's Disease Patient Registry is the one named on this page) and document the enrollment ID. |
| MRI schedule not on file | Baseline or month 1, 2, 3 or 6 MRI missing from the chart | Complete the scheduled scan and document ARIA findings before the next infusion. |
| Units not matching weight × 10 | Billed units do not equal the patient's weight in kg × 10 mg/kg | Recalculate units as weight (kg) × 10 and resubmit. |
| Interval shorter than 2 weeks | Infusion billed less than 14 days after the prior dose | Confirm the date of service against the 2-week starting interval (or 4-week maintenance interval) before submitting. |
| Maintenance q4wk billed before 18 months | Claim uses the every-4-week interval before the patient has completed 18 months on the starting regimen | Confirm the starting-regimen date and hold q4wk billing until 18 months have elapsed. |
Frequently asked questions
What is the J code for Leqembi?
Leqembi (lecanemab-irmb) bills under HCPCS J0174, where 1 billing unit equals 1 mg. An 80 kg patient at the standard 10 mg/kg dose receives 800 mg, reported as 800 units of J0174 on the administered line.
Is Leqembi billed with 96365 or 96413?
96365 (therapeutic infusion, initial hour). Leqembi is an anti-amyloid monoclonal antibody, not a chemotherapy agent, so 96413 and 96415, the chemotherapy administration codes, are the wrong family. The roughly one-hour infusion is 96365 alone; 96366 (each additional hour) applies only if the infusion runs more than 30 minutes past the first hour.
How many units of Leqembi does an 80 kg patient need?
At the standard 10 mg/kg dose, an 80 kg patient receives 800 mg, billed as 800 units of J0174 (1 unit = 1 mg). The fewest-vials draw pulls two 500 mg vials (1,000 mg total), administers 800 mg, and reports the unused 200 mg on a separate J0174 line with modifier JW.
What is the dosing for lecanemab-irmb by indication?
Lecanemab-irmb is dosed by weight at 10 mg/kg, first every 2 weeks and, after 18 months, every 4 weeks if the prescriber chooses; there is no separate induction dose:
- Starting regimen = 10 mg/kg every 2 weeks
- Maintenance = 10 mg/kg every 4 weeks
How often is Leqembi given?
Every 2 weeks by IV infusion for the first 18 months. After 18 months, the prescriber may continue every 2 weeks or move to IV maintenance every 4 weeks at the same 10 mg/kg dose; the label also offers a weekly subcutaneous maintenance option, LEQEMBI IQLIK.
How is Leqembi waste billed?
Discarded drug from a single-dose vial goes on a separate J0174 line with modifier JW. For an 800 mg dose, the fewest-vials draw takes two 500 mg vials (1,000 mg), administers 800 mg, and reports the remaining 200 mg as JW. A dose with no discard, drawn as an exact multiple of the vial sizes, takes modifier JZ instead.
Does Medicare cover Leqembi?
Yes, under NCD 200.3, coverage with evidence development: the prescriber enrolls the patient in a CMS-approved registry (NACC's Alzheimer's Disease Patient Registry is the one named on this page), and registry enrollment plus the amyloid result are claim facts. Commercial payers separately require the biomarker, staging and an MRI, and reauthorize on documented response.
Is Leqembi Iqlik billed with J0174?
No. LEQEMBI IQLIK is the subcutaneous autoinjector (500 mg weekly starting, 360 mg weekly maintenance) that the patient self-administers at home. It is not an office-administered infusion, so it does not bill under J0174; the IV product does.
Sources
- FDA label (DailyMed), LEQEMBI (lecanemab-irmb), revised 7/2026
- CMS, Medicare Part B Drug ASP Pricing File, Q4 2026
- CMS, Physician Fee Schedule Look-Up Tool
- CMS, NCD 200.3, coverage with evidence development
- Eisai patient support, LEQEMBI Copay Assistance and LEQEMBI Patient Assistance Program (free drug), part of LEQEMBI Companion
- 20 commercial payer policies, current as of Aug 2026
Dataset dates: pricing Q4 2026 · payer policies Aug 2026 · assistance Apr 2026.
Reviewed September 20, 2026 by Erin Rose, CareCost Estimate founder. Methodology →