Leqembi (J0174): Medicare coverage & FDA-indicated diagnoses

Leqembi (Lecanemab-irmb) · Medicare Part B (physician-administered) · 4 FDA-indicated ICD-10 codes

Medicare pays for Leqembi (J0174) under Part B per medical necessity. There is no drug-specific Medicare LCD, so the 4 ICD-10 codes below are the FDA-approved indications — the labeled uses Medicare generally pays for — grouped by condition. Coverage is judged by your MAC. Page reviewed Aug 23, 2026.

Page reviewed Aug 23, 2026 · from FDA-approved labeling (Drugs@FDA) — no drug-specific Medicare LCD

Quick answer

Medicare benefit
Part B (physician-administered)
FDA-indicated diagnoses
4 ICD-10 codes
Governing policy
FDA indications (no LCD)
Contractor (MAC)
Per medical necessity
Source
FDA labeling
Page reviewed
Aug 23, 2026
HCPCS codes covered:
J0174
No drug-specific Medicare coverage article exists for Leqembi. Coverage is decided per medical necessity by your MAC. The FDA-approved indications below are the labeled uses Medicare generally pays for; an off-label use may be covered if supported by an approved compendium. Find your MAC by state →

What Medicare pays for Leqembi (2026 Q3)

Once a claim carries a covered diagnosis, Medicare Part B reimburses the drug at the ASP + 6% payment limit. Current allowed amounts per billing unit:

HCPCSDescriptionPer unitAllowed (ASP + 6%)
J0174Inj, lecanemab-irmb, 1 mg1 mg$1.342

Source: CMS ASP Drug Pricing File, 2026 Q3. Payment = ASP + 6% per unit; multiply by units billed (watch JZ/JW wastage). Your patient's share is typically 20% after the deductible. Estimate the full cost & patient out-of-pocket →

Worked billing example for Leqembi

A concrete, paste-checkable example using J0174’s own billing-unit basis and vial sizes — not a hypothetical.

Scenario700 mg dose — 10 mg/kg IV q2wk for a 70 kg reference patient
Dose administered700 mg
Billing unit basis1 unit = 1 mg
Billing units (dose ÷ unit basis, rounded up)700 units of J0174
Vial combination drawn (min-waste plan)1 × 500 mg vial + 1 × 200 mg vial
Discarded (waste)None
Wastage modifier (JW / JZ)Bill all 700 units on a single line with JZ (attests zero drug discarded). What JZ/JW mean →
Medicare allowable (ASP + 6%, 2026 Q3)700 units × $1.342/unit = $939.40

This is Medicare’s allowable payment limit (ASP + 6%, 2026 Q3) — not a promise of what you will be paid. Actual paid amount depends on sequestration and whether the claim carries a covered diagnosis.

Dose source: drugs/leqembi.html — FAQ: "For a 70 kg patient: 700 mg = 700 units.". Different dose or drug? Compute your own dose → or estimate the full cost & patient out-of-pocket →.

Leqembi is a physician-administered biologic billed under Medicare Part B (not the Part D pharmacy benefit). Under Part B, Medicare pays the practice for the drug (HCPCS J0174) plus its administration — but only when the claim's diagnosis (ICD-10) code supports medical necessity. Each MAC publishes the specific covered diagnoses in a Billing & Coding Article; a claim with a diagnosis outside that list is typically denied as not medically necessary (CO-50).

Covered ICD-10 diagnoses for Leqembi

The 4 FDA-approved indications for J0174, grouped by condition — filter to find a code.

Alzheimer Disease — 4 diagnoses (applies to J0174)

Diseases of the nervous system (4)

ICD-10Covered diagnosis
G30.0Alzheimer disease with early onset
G30.1Alzheimer disease with late onset
G30.8Other Alzheimer's disease
G30.9Alzheimer disease, unspecified

What commercial payers require for Leqembi

Medicare Part B is only half the answer — most Leqembi claims are adjudicated by a commercial plan with its own medical policy. Below is what 20 commercial payers publish for Leqembi, read from each payer's own policy document. 18 of 20 that state a position require prior authorization, and 3 run a site-of-care program that can push the infusion out of the hospital outpatient setting.

PayerPrior authPreferred product firstSite of careIndications namedPolicy date
Aetna policy ↗RequiredSite of Care Utilization Management Policy applies22026-01-27
Anthem / Elevance policy ↗Required22025-10-07
BCBS Federal Employee Program policy ↗Required22025-07-01
BCBS Kansas policy ↗Required2
BCBS Massachusetts policy ↗Required22026-01-15
BCBS Minnesota policy ↗Required22025-10-02
BCBS Mississippi policy ↗Required2
BCBS South Carolina policy ↗Not required2
BCBS Tennessee policy ↗Required22023-05-02
Blue Shield of California policy ↗Required22026-04-01
Capital BlueCross policy ↗Required22025-10-02
CareFirst BCBS policy ↗Required1
Centene / Ambetter policy ↗Required22023-01-06
Florida Blue policy ↗Required22026-06-01
HCSC (IL/TX/OK/NM/MT) policy ↗Not requiredSite-of-care program applies22025-08-15
HMSA (BCBS Hawaii) policy ↗Required22025-02-01
Premera Blue Cross policy ↗Required22026-07-01
Regence BCBS policy ↗RequiredLeqembi (lecanemab) coverable under the medical benefit22026-04-01
UnitedHealthcare policy ↗Required22026-04-01
Wellmark BCBS policy ↗Required22023-06-01

What Leqembi payers put in writing

Quoted from the medical policies linked above — 24 distinct requirements across 20 payers. These are the sentences an appeal has to answer.

Clinical prerequisites — what must be true before they pay

Prior authorization

Quantity and frequency limits

Dosing rules

Reauthorization / continuation

Site-of-care restrictions

Read from each payer's published medical policy between 2026-08-03 and 2026-08-13. Every requirement above is quoted from the policy it links to. Commercial policy changes without notice — confirm before you bill.

How to bill Leqembi

Put a medically necessary, FDA-indicated diagnosis from the list above on the claim line with J0174. Matching codes, units and JZ/JW wastage →

Which policy governs Leqembi

No drug-specific LCD or Article — see the note at the top of this page. Find your MAC → What an LCD, an Article and an NCD each govern →

If a claim for Leqembi is denied

With no drug-specific Article, the usual cause is a diagnosis the MAC does not accept as medically necessary for J0174, or an off-label use with no compendium support. The five denial patterns and how to fix each →

Frequently asked questions

Is Leqembi covered by Medicare?
Yes. Leqembi (J0174) is covered under Medicare Part B as a physician-administered drug when billed for a medically necessary indication. There is no drug-specific Local Coverage Determination (LCD) for it, so coverage is determined per medical necessity by your MAC; the FDA-approved indications below are the starting point.
What diagnoses are covered for Leqembi (J0174)?
Medicare publishes no drug-specific covered-diagnosis list for J0174. The 4 ICD-10 codes here are the FDA-approved indications; an off-label use needs approved-compendium support (DrugDex, NCCN) to be payable.
Which Medicare policy covers Leqembi?
No drug-specific LCD or Billing & Coding Article exists for Leqembi. It's covered under the general Medicare Part B drug benefit per medical necessity, as judged by your Medicare Administrative Contractor (MAC).
Why was my Leqembi claim denied as not medically necessary?
The most common cause is a diagnosis the MAC doesn't consider medically necessary for J0174. Bill a covered/FDA-approved indication from the list below, document medical necessity, and confirm any local guidance with your MAC.

Related references

Covered is only half the answer.

You know the diagnosis is payable. Now quote the patient before the visit and catch underpayments: get Leqembi's exact Medicare allowed amount, your payer's rate vs. ASP+6%, and the patient's out-of-pocket — in about 30 seconds, free.

Estimate Leqembi cost & patient owe →

Source & verification

Source
FDA-approved indications (Drugs@FDA labeling) mapped to ICD-10-CM. No drug-specific Medicare LCD/Article exists for Leqembi — Part B coverage is determined per medical necessity by your MAC.
Primary sources
DailyMed — Leqembi prescribing information · CMS Part B Drug ASP Pricing File — the quarterly payment limit quoted above · CMS Medicare Coverage Database — searched for “Leqembi”; no drug-specific NCD, LCD or Billing & Coding Article exists, which is why the FDA-indicated codes above are the working list
Page last reviewed by CareCost
Aug 23, 2026 (coverage data retrieved 2026-08-26; we re-verify against CMS quarterly).
Code licensing
ICD-10-CM codes are public domain (CMS/CDC). CPT® codes are AMA-copyrighted and are intentionally not listed here — see the administration-code reference for those.
Not advice
This is general billing reference, not legal or billing advice. Always verify against the LCD/Article that applies to your MAC and patient.
How we build this
Compiled programmatically from the CMS Coverage API under a founder-led methodology maintained by Erin Rose (Founder), and reviewed against the source article with a practitioner-correction loop. See our methodology and editorial policy.
Spotted an error?
Email editorial@carecostestimate.com.