Leqembi is the brand name for lecanemab-irmb, a humanized monoclonal antibody that targets amyloid-beta protein in the brain. Eisai co-develops and markets Leqembi with Biogen for adults with mild cognitive impairment or mild dementia due to Alzheimer's disease. The FDA granted Leqembi accelerated approval in January 2023 and full traditional approval in July 2023, based on the Clarity AD trial showing a 27 percent slowing of cognitive decline over 18 months compared to placebo. Leqembi is given as an intravenous infusion every two weeks in a doctor's office, infusion center, or hospital outpatient department. In October 2025, Eisai launched Leqembi IQLIK, a once-weekly subcutaneous autoinjector approved for maintenance dosing after 18 months of infusions. Both forms carry a boxed warning for ARIA (amyloid-related imaging abnormalities), a type of brain swelling or bleeding that requires periodic MRI monitoring.
Eisai's 2026 list price for Leqembi remains weight-based: patients receive 10 milligrams per kilogram of body weight every two weeks, so the annual cost ranges from about $26,500 to $32,000 depending on the patient's weight. Medicare Part B, not Part D, pays for the intravenous form because it is administered in a clinical setting under HCPCS code J0174. Medicare covers Leqembi under a National Coverage Determination for monoclonal antibodies directed against amyloid, first issued in June 2023 and broadened after Leqembi's traditional FDA approval. Coverage requires a documented diagnosis of mild cognitive impairment or mild dementia due to Alzheimer's disease, confirmed amyloid pathology through a PET scan or cerebrospinal fluid test, and enrollment in a CMS-approved registry that tracks outcomes and safety data such as ARIA rates. Without insurance, a single infusion can run $1,000 to $1,300 depending on the patient's weight and the site of care, and hospital outpatient departments frequently add facility fees on top of the drug charge.
The Inflation Reduction Act of 2022 lets Medicare negotiate prices for some high-spend drugs, but biologics like Leqembi are shielded from negotiation for 13 years after FDA approval, so Leqembi will not be eligible for a Maximum Fair Price before 2036 at the earliest. Eli Lilly's Kisunla (donanemab) is a competing anti-amyloid monoclonal antibody with a similar Medicare National Coverage Determination and a comparable price point, but Kisunla is dosed monthly rather than every two weeks and has a fixed treatment endpoint once amyloid plaques clear. Patients weighing Leqembi against Kisunla should ask their neurologist about scan-confirmed stopping criteria. For broader Medicare enrollment questions, see Medicare eligibility rules; for the underlying poverty-guideline math behind Eisai's patient assistance program, see the federal poverty level chart.
What Leqembi Costs by Point of Pay (2026)
The price you pay depends almost entirely on WHERE you pay. The same leqembi can cost many times more at a hospital than at your local pharmacy:
2026 Leqembi Price by Point of Pay| Where you pay | Typical cost | Notes |
|---|
| Medicare ASP rate (Part B, HCPCS J0174) | $1.25/mg ASP; Medicare pays ASP + 6%, about $1.32/mg in 2026 | Applies only to the intravenous infusion form given in a clinical setting. |
| Infusion center or hospital outpatient (cash, no insurance) | $26,500 - $32,000/year (weight-based dosing) | List price for biweekly IV infusions at 10 mg/kg; does not include facility fees. |
| Medicare Part B (beneficiary coinsurance, 2026) | $283 deductible, then 20% coinsurance (about $5,300 - $6,400/year) | The 2026 Part B deductible is $283; coinsurance applies after the deductible is met. |
| Commercial insurance | $0 - $500/month after prior authorization | Requires documented MCI/mild dementia diagnosis, confirmed amyloid pathology, and often an in-network infusion site. |
| Eisai copay assistance card | As little as $0/infusion, up to $10,000/year | Commercial insurance only; not valid for Medicare, Medicaid, TRICARE, VA, or DoD beneficiaries. |
| Medicaid | $0 - $4/service, with prior authorization | Coverage and PA criteria vary by state; dual-eligible patients typically owe nothing under QMB protections. |
Prices reflect 2026 Medicare Part B ASP files and Eisai's published list price. Actual patient cost depends on body weight, dosing schedule, site of care, and insurance plan design.
Source: CMS Medicare Part B ASP Drug Pricing Files (2026), Eisai LEQEMBI list price, CMS National Coverage Determination for Monoclonal Antibodies Directed Against Amyloid
Why Hospitals Charge So Much
Hospital outpatient departments bill Leqembi infusions differently than independent infusion centers or neurology offices. A hospital-owned site typically adds a facility fee on top of the drug charge itself, along with nursing time, monitoring, and overhead for the MRI scans required to watch for ARIA. Independent infusion centers and physician offices generally charge closer to the Medicare ASP-based rate because they lack the added facility designation. For a drug priced at $26,500 to $32,000 a year, that facility markup can push the annualized hospital outpatient bill to $34,000 or more even when the underlying drug cost has not changed.
Eisai's LEQEMBI Companion Program can tell patients which nearby infusion sites are in-network and lower-cost before treatment starts. Patients who receive an itemized bill well above the $26,500 to $32,000 range should ask the billing office for the National Drug Code, the exact milligram dose administered relative to body weight, and a breakdown of the facility fee versus the drug charge. Switching from a hospital outpatient department to an independent infusion center or in-office infusion, when clinically appropriate, is one of the most reliable ways to lower the annual cost of Leqembi treatment without changing the drug itself.
HCPCS J-Codes: What Appears on Your Bill
Leqembi's intravenous infusion form is billed under a single HCPCS Level II code that identifies the milligram dose administered.
HCPCS J-codes for Leqembi| Code | Description | What to look for |
|---|
| J0174 | Lecanemab-irmb, for intravenous injection, 1 mg | Confirm the billed units match 10 mg/kg of the patient's actual body weight per infusion; a mismatch inflates the bill. |
J0174 applies to the intravenous infusion form only. Leqembi IQLIK, the subcutaneous autoinjector, is typically billed through a specialty pharmacy under Medicare Part D or a commercial pharmacy benefit rather than a J-code.
Source: CMS HCPCS Level II code file, effective July 6, 2023
Patient Assistance Programs
Eisai runs the LEQEMBI Companion Program, which combines insurance benefits verification, a commercial copay assistance card, and a separate income-based patient assistance program for uninsured or underinsured patients who cannot afford Leqembi without insurance.
Patient assistance programs for Leqembi| Manufacturer program | Cost / Benefit | How to apply |
|---|
| LEQEMBI Companion Program (Eisai Patient Assistance Program) | Free Leqembi for a rolling 12-month period for patients at or below 300% of the federal poverty level who are uninsured or underinsured | leqembienrollment.com |
| LEQEMBI Copay Assistance Program | As little as $0 per infusion; Eisai covers up to $10,000 per calendar year in out-of-pocket costs for commercially insured patients | eisaipatientsupport.com |
| NeedyMeds Drug Discount Card | Variable discount at participating pharmacies; generally does not apply to hospital-billed IV infusions | needymeds.org |
Every Leqembi manufacturer coupon and copay assistance card, including the LEQEMBI Copay Assistance Program, is invalid for patients enrolled in Medicare, Medicaid, Medigap, VA, DoD, or TRICARE. Federal anti-kickback law (42 U.S.C. Section 1320a-7b) bars manufacturers from subsidizing copays for government health program beneficiaries. Medicare and Medicaid patients should apply to the income-based LEQEMBI Companion Program instead.
Source: Eisai Patient Support / LEQEMBI Companion Program, NeedyMeds.org
Medicare Part D
Leqembi IQLIK, the once-weekly subcutaneous autoinjector Eisai launched in October 2025 for maintenance dosing, is typically billed through Medicare Part D or a commercial pharmacy benefit because patients or caregivers self-administer it at home rather than in a clinical setting. In 2026, the annual Part D out-of-pocket cap is $2,100 across all covered drugs combined, so a patient's total spending on Leqembi IQLIK and any other Part D prescriptions cannot exceed that amount in a calendar year. Every Part D plan places Leqembi IQLIK on a formulary tier, usually the specialty tier, and that formulary tier assignment drives the initial coinsurance a patient owes before reaching the cap.
Original Medicare Part B, not Part D, remains the primary payer for the intravenous Leqembi infusions given during the first 18 months of treatment. Patients typically start on IV infusions, confirm amyloid clearance on a follow-up scan, and then may transition to the once-weekly IQLIK autoinjector for maintenance. Because the two forms of Leqembi fall under different parts of Medicare, a patient's out-of-pocket math changes meaningfully depending on which form their neurologist prescribes and when in the treatment course they switch.
Common Leqembi Billing Errors
Leqembi bills that come in well above the Medicare ASP-based rate or the $26,500 to $32,000 annual list price often trace back to one of these errors:
- J0174 units billed do not match the patient's actual weight-based dose, effectively double-billing part of the infusion.
- CMS registry enrollment was never completed or documented, causing Medicare to deny the claim under the National Coverage Determination even though the patient met the clinical criteria.
- The amyloid PET scan or cerebrospinal fluid confirmation was missing from the prior authorization request, triggering an avoidable denial.
- Hospital outpatient facility fees were stacked on top of the drug charge without a separate line item, making it impossible to see the actual drug cost.
- Eisai's copay assistance card was applied incorrectly to a Medicare or Medicaid claim, which is not allowed under the program's terms and can trigger a clawback.
- Leqembi IQLIK was billed under the intravenous J-code (J0174) instead of the correct Part D or pharmacy benefit pathway for the subcutaneous autoinjector.
Frequently Asked Questions
Does Medicare cover Leqembi for Alzheimer's in 2026?
Yes. Medicare Part B covers Leqembi (lecanemab-irmb) intravenous infusions under a national coverage determination for monoclonal antibodies directed against amyloid. Coverage requires a documented diagnosis of mild cognitive impairment or mild dementia due to Alzheimer's disease, confirmed amyloid pathology through a PET scan or cerebrospinal fluid test, and enrollment in a CMS-approved registry. In 2026, you pay the $283 Part B deductible, then 20% coinsurance, which runs about $5,300 to $6,400 a year on the $26,500 to $32,000 annual list price. The once-weekly Leqembi IQLIK maintenance autoinjector is typically billed under Medicare Part D instead.
Is there a generic or biosimilar for Leqembi?
No. Leqembi (lecanemab-irmb) is a biologic monoclonal antibody, not a small-molecule drug, so it cannot have a generic. Biosimilars are legally possible, but Leqembi's 12 to 13 year biologics market exclusivity, running from its July 2023 traditional FDA approval, means no biosimilar competitor is expected before the mid-2030s at the earliest. Eli Lilly's Kisunla (donanemab) is a similar anti-amyloid monoclonal antibody, but it is a distinct product, not a generic or biosimilar of Leqembi.
How do I apply for the Eisai LEQEMBI patient assistance program?
Start at leqembienrollment.com or call Eisai Patient Support at 1-833-453-7362. Your neurologist's office completes a joint enrollment form with your diagnosis and prescription, and you submit proof of household income and insurance status. Eisai reviews the application and, if approved, enrolls you for a rolling 12-month period during which you must receive all Leqembi doses through the program. Household income must be at or below 300% of the federal poverty level for 2026. Processing typically takes one to two weeks.
Can I use the Leqembi copay card with Medicare?
No. The LEQEMBI Copay Assistance Program explicitly excludes patients enrolled in Medicare, Medicaid, Medigap, VA, DoD, or TRICARE. Federal anti-kickback law (42 U.S.C. Section 1320a-7b) bars drug manufacturers from subsidizing copays for beneficiaries of government health programs, since that could improperly steer treatment decisions. If you have Medicare, your best option is the separate, income-based LEQEMBI Companion Program, which can provide Leqembi at no cost if your household income is at or below 300% of the federal poverty level in 2026.
What if my insurance denies coverage for Leqembi?
Request the written denial letter and the specific reason cited, since most Leqembi denials trace to missing amyloid PET or cerebrospinal fluid confirmation, incomplete registry enrollment, or a diagnosis code that does not match mild cognitive impairment or mild dementia due to Alzheimer's disease. Ask your neurologist to file a peer-to-peer review with the missing documentation attached, then a formal written appeal within your plan's deadline, typically 60 days. If the appeal fails, request external review through your state insurance department, and apply to Eisai's LEQEMBI Companion Program as a financial backstop while you appeal.
Does the Inflation Reduction Act's negotiated price apply to Leqembi?
Not yet. Leqembi has not been selected for Medicare price negotiation. The Inflation Reduction Act of 2022 exempts biologics like Leqembi from negotiation for 13 years after FDA approval, so Leqembi will not be eligible for a Maximum Fair Price before 2036 at the earliest, based on its July 2023 traditional approval date. For now, Leqembi costs fall under the standard 2026 Medicare Part B deductible ($283) and 20% coinsurance structure, or the $2,100 annual Part D out-of-pocket cap for the self-administered Leqembi IQLIK maintenance dose.
What does Leqembi cost without insurance in 2026?
Without insurance, Leqembi's list price runs about $26,500 to $32,000 a year because dosing is based on body weight at 10 mg/kg every two weeks. A single infusion typically costs $1,000 to $1,300 in drug charges alone, before any facility fee at a hospital outpatient department. Leqembi IQLIK, the once-weekly subcutaneous maintenance autoinjector, carries a separate wholesale acquisition cost of $385 per autoinjector, or about $20,020 a year. Uninsured patients at or below 300% of the federal poverty level can apply for free Leqembi through Eisai's LEQEMBI Companion Program.
What is the difference between Leqembi and Kisunla?
Leqembi (lecanemab-irmb, Eisai and Biogen) and Kisunla (donanemab, Eli Lilly) are both anti-amyloid monoclonal antibodies covered under the same Medicare National Coverage Determination, and both require confirmed amyloid pathology and CMS registry enrollment. Leqembi is infused every two weeks indefinitely, or transitions to a once-weekly subcutaneous autoinjector (Leqembi IQLIK) for maintenance. Kisunla is infused once a month and has a defined stopping point once follow-up PET scans confirm amyloid plaques have cleared, which can shorten total treatment cost. Ask your neurologist which scan-confirmed protocol fits your diagnosis.
