Kisunla (donanemab-azbt) — HCPCS J0175

Unit basis — the 2 mg trap CMS HCPCS verified May 2026

J0175 is one of a small number of HCPCS J-codes that does NOT use 1 mg per unit.

The HCPCS Level II descriptor for J0175 is "Injection, donanemab-azbt, 2 mg." Each billable unit equals 2 mg of donanemab. This is unusual — the vast majority of injectable biologics (Leqembi J0174, Opdivo J9299, Keytruda J9271, etc.) use 1 mg per unit. The 2 mg unit basis is the most common biller error on Kisunla.

Quick conversion table

Dosing & unit math FDA label rev Dec 30, 2025

From the FDA prescribing information, full approval July 2, 2024 (BLA 761248); label updated December 30, 2025 to the lower-ARIA "Dosing Regimen 2."

Titration phase — doses 1 through 3 (ascending, NEW Regimen 2)

• Dose 1: 350 mg IV — 1 × 350 mg vial — bill 175 units of J0175
• Dose 2: 700 mg IV (q4wk) — 2 × 350 mg vials — bill 350 units
• Dose 3: 1,050 mg IV (q4wk) — 3 × 350 mg vials — bill 525 units
• Each dose infused IV over ~30 minutes; no waste (whole-vial dosing)

Maintenance phase — dose 4 onward

• 1,400 mg IV every 4 weeks starting at month 4
• Four 350 mg vials per dose — no waste
• Bill 700 units of J0175 per dose (1,400 mg ÷ 2 mg per unit)
• Continue until amyloid PET shows clearance (see Treatment discontinuation)

Worked example — first-year billing (Regimen 2)

No premedication routinely required

FDA label does NOT mandate routine pre-infusion premedication. Some clinics use diphenhydramine or acetaminophen for patients with prior infusion reactions. Have epinephrine and resuscitation equipment on site — anaphylaxis is in the boxed warning.

Kisunla vs Leqembi — bill them differently Cross-reference verified May 2026

Same therapeutic class (anti-amyloid mAb for early AD) — six major billing differences.

NDC reference FDA NDC Directory verified May 2026

Pre-treatment workup FDA label + CMS NCD 210.20

Four mandatory items before the first Kisunla infusion. Schedule and bill these in the right order.

APOE genotype testing FDA label Jul 2024

APOE4 homozygotes have the highest ARIA risk on Kisunla — ~40% incidence per the TRAILBLAZER-ALZ 2 trial.

Why it matters for billing

The FDA label specifically calls out APOE4 homozygotes as the highest-risk subgroup for amyloid-related imaging abnormalities (ARIA) on Kisunla — approximately 40% incidence vs ~22% for heterozygotes and ~14% for non-carriers. This is the highest reported ARIA rate of any anti-amyloid mAb. APOE genotype must be documented in the chart before the first infusion, and the patient must be counseled about their specific risk tier.

Test code

• CPT 81401 — molecular pathology procedure level 2 (covers APOE genotyping)
• Also reported under 81406 by some labs depending on methodology
• Most commercial payers cover when ordered before anti-amyloid mAb initiation
• Medicare coverage varies by MAC; document medical necessity (anti-amyloid candidate) on the order

MRI surveillance schedule FDA label Jul 2024

Four mandatory surveillance MRIs after baseline. Different schedule from Leqembi.

MRI billing

• CPT 70551 — MRI brain without contrast (most common for ARIA surveillance)
• CPT 70553 — MRI brain with and without contrast (when ARIA suspected)
• Bill on a separate claim line from the infusion claim
• Document indication: "anti-amyloid mAb surveillance per FDA label" with the J0175 ICD-10

Administration codes CPT verified May 2026

Donanemab is a non-chemotherapy biologic. Use therapeutic IV codes, not chemo admin codes.

Modifiers CMS verified May 2026

JZ — required on virtually every Kisunla claim

Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. Kisunla is supplied in 350 mg single-dose vials, and each labeled dose is a clean whole-vial multiple (350 mg = 1 vial, 700 mg = 2 vials, 1,050 mg = 3 vials, 1,400 mg maintenance = 4 vials) with zero waste. JZ applies to virtually every Kisunla claim.

JW — only for off-protocol partial-vial waste

JW reports the discarded portion of a single-dose vial. For Kisunla, JW would only apply if a clinician adjusted the dose off-protocol (e.g., temporarily lowered to manage tolerability), creating partial-vial waste. Bill the JW line for the discarded portion in addition to the JZ-style admin line for the units administered. One of JZ or JW must be on every J0175 claim.

Modifier 25 — same-day E/M

Use modifier 25 on the E/M code when a significant, separately identifiable evaluation and management service is performed on the same day as the infusion (e.g., post-MRI ARIA review with the neurologist). Routine pre-infusion clinical assessment is bundled.

340B modifiers (JG, TB)

For 340B-acquired Kisunla, follow your MAC's current 340B modifier policy. Lilly's billing guide does not provide 340B-specific instructions for J0175.

ICD-10-CM by AD stage FY2026 verified May 2026

Kisunla is approved ONLY for early symptomatic AD (mild cognitive impairment OR mild dementia stage). Stage matters.

Site of care & place of service Verified May 2026

Anti-amyloid mAbs require ARIA monitoring infrastructure and access to MRI — site-of-care choice affects both safety and reimbursement. Most commercial payers prefer office or AIC over HOPD.

Claim form field mapping Lilly HCP coding 2026

CMS Coverage with Evidence Development (CED) registry CMS NCD 210.20

Mandatory for Medicare Part B coverage of any anti-amyloid mAb (Kisunla, Leqembi).

On April 7, 2022 (and updated for full-approval drugs in 2023), CMS finalized National Coverage Determination 210.20 covering monoclonal antibodies directed against amyloid for AD. Per the NCD, Medicare Part B covers Kisunla and Leqembi only when:

• Prescribed by a qualified physician (typically neurology, geriatric medicine, geriatric psychiatry)
• Patient has clinically meaningful early symptomatic AD (MCI or mild dementia stage)
• Confirmed amyloid pathology (PET or CSF)
• Prescribing physician is enrolled in a CMS-approved registry that collects clinical and adverse-event data on participating patients

Approved registries

• ALZ-NET (Alzheimer's Network for Treatment and Diagnostics) — the most widely-used registry, free for clinicians, web-based data entry. alz-net.org
• Health-system-specific registries that have been CMS-approved (verify with the practice's MAC)

Payer policy snapshot Reviewed May 2026

All major payers require PA. Most also require amyloid pathology, APOE genotype, baseline MRI, and (for Medicare) CED registry.

Step therapy

Step therapy through Leqembi is generally NOT required for Kisunla initiation. Some plans require documentation that the prescriber considered both options and selected based on clinical factors (q4wk vs q2wk preference, fixed vs weight-based dosing, ARIA risk profile, treatment duration goals). PA criteria focus on diagnosis, biomarker, APOE, and registry enrollment — not prior anti-amyloid use.

Medicare reimbursement CMS Q2 2026 (live)

Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter. Remember: 1 unit = 2 mg.

Coverage

Coverage is governed by CMS NCD 210.20 (Monoclonal Antibodies Directed Against Amyloid for the Treatment of Alzheimer's Disease) plus MAC-level LCDs. NCD requires CED registry participation. MACs further specify documentation expectations, site-of-care preferences, and ARIA management standards.

Code history

• Pre-2025: billed under unclassified J3490 (drugs not otherwise classified) with NDC 00002-2024-01 and dose documentation
• J0175 — permanent code, effective January 1, 2025, descriptor "Injection, donanemab-azbt, 2 mg"

Patient assistance — Lilly programs Lilly verified May 2026

• Lilly Answers Center: 1-800-545-5979 — benefits investigation, prior authorization assistance, appeal support
• Kisunla Co-Pay Assistance Program: commercial copay support; eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients). Verify current copay cap at kisunla.com.
• Lilly Cares Foundation Patient Assistance Program: free product for uninsured / underinsured patients meeting income requirements (administered through Lilly Cares Foundation, Inc., a 501(c)(3))
• Foundations for Medicare patients: PAN Foundation, HealthWell Foundation, Alzheimer's Association assistance funds — verify open AD funds quarterly (Alzheimer's funds open and close more frequently than oncology funds)
• Web: kisunla.com / lillypatientone.com

Treatment discontinuation — the amyloid PET clearance criterion FDA label Jul 2024 · major Kisunla differentiator

Unique to Kisunla: per the FDA label, donanemab can be DISCONTINUED when amyloid PET shows clearance. Major billing implication.

Kisunla's distinguishing feature versus Leqembi: per the FDA label (full approval July 2024), donanemab can be stopped when amyloid PET imaging confirms amyloid clearance. In the TRAILBLAZER-ALZ 2 pivotal trial, approximately 17% of patients reached amyloid clearance threshold by 6 months, ~47% by 12 months, and ~69% by 18 months. After clearance is documented, continued infusion is not indicated.

Practical workflow

• Repeat amyloid PET at 12 months (some practices use 18 months) — CPT 78814/78815 + tracer A-code
• If amyloid cleared: document in chart, discontinue Kisunla, transition to surveillance / supportive care
• If amyloid not yet cleared: continue maintenance dosing, plan repeat PET at 18–24 months
• If amyloid re-accumulates after clearance: discuss re-initiation with patient and document new amyloid pathology

Billing implications

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Kisunla?

Kisunla (donanemab-azbt) is billed under HCPCS J0175 — "Injection, donanemab-azbt, 2 mg." Each billable unit equals 2 mg of donanemab, NOT 1 mg as with most biologics. Under the current label (Dosing Regimen 2), the 350 mg dose 1 is billed as 175 units, the 700 mg dose 2 as 350 units, the 1,050 mg dose 3 as 525 units, and each 1,400 mg maintenance dose as 700 units. J0175 became effective January 1, 2025. Pre-permanent-code claims used unclassified J3490.

How many units do I bill for a Kisunla dose?

Divide the mg administered by 2. Dose 1 (350 mg) = 175 units. Dose 2 (700 mg) = 350 units. Dose 3 (1,050 mg) = 525 units. Dose 4 onward (1,400 mg maintenance) = 700 units. Common biller error: billing mg as units, which doubles billed units and triggers denial or overpayment recoupment.

What administration CPT do I use for Kisunla?

CPT 96365 — "Intravenous infusion, for therapy, prophylaxis, or diagnosis; initial, up to 1 hour." Donanemab is a non-chemotherapy biologic so chemo admin codes (96413, 96415) are NOT appropriate. Standard infusion is ~30 minutes, well within the 1-hour 96365 window. Add 96366 only if infusion extends beyond 1 hour (rare).

Do I bill JZ or JW for Kisunla?

Bill JZ on virtually every Kisunla claim. Kisunla is supplied in 350 mg single-dose vials and every labeled dose is a whole-vial multiple (350 / 700 / 1,050 / 1,400 mg = 1 / 2 / 3 / 4 vials) with no waste. JW only applies if a partial-vial waste scenario occurs (off-protocol dose adjustments). One of JZ or JW must be on every J0175 claim per CMS's July 2023 single-dose container policy.

What is the Medicare reimbursement for J0175?

For Q2 2026, the Medicare Part B payment limit for J0175 is $4.140 per 2-mg unit (ASP + 6%), or $2.070 per mg. Per-dose reimbursement (Regimen 2): 350 mg (175 units) ≈ $724.50; 700 mg (350 units) ≈ $1,449.00; 1,050 mg (525 units) ≈ $2,173.50; 1,400 mg maintenance (700 units) ≈ $2,898.00. First-year drug cost (3 titration + 10 maintenance doses): approximately $33,327. Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.

Does Medicare require a registry for Kisunla coverage?

Yes. Per CMS National Coverage Determination 210.20 (Monoclonal Antibodies Directed Against Amyloid for the Treatment of Alzheimer's Disease), Medicare covers anti-amyloid monoclonal antibodies including Kisunla and Leqembi only when prescribed by a qualified physician, the patient has a confirmed amyloid pathology diagnosis, and the prescribing physician participates in a CMS-approved Coverage with Evidence Development (CED) registry that collects clinical and adverse-event data. Most providers use the ALZ-NET registry. Without registry enrollment, Medicare will deny J0175.

What pre-treatment workup is required for Kisunla?

Three mandatory items before the first infusion: (1) confirmed amyloid pathology — either amyloid PET scan (CPT 78814/78815 with radiotracer) or CSF biomarker testing (CPT 83520 for amyloid-beta 42/40 ratio); (2) APOE genotyping (CPT 81401) — APOE4 homozygotes have approximately 40% ARIA incidence on Kisunla, the highest risk group; (3) baseline brain MRI within 1 year (CPT 70551 or 70553) to assess for pre-existing microhemorrhages, siderosis, or vasogenic edema. Plus CMS CED registry enrollment for Medicare coverage.

How does Kisunla compare to Leqembi for billing?

Six major billing differences: (1) Unit basis — J0175 is 2 mg per unit; J0174 (Leqembi) is 1 mg per unit. (2) Dosing — Kisunla is fixed (700 then 1,400 mg); Leqembi is weight-based (10 mg/kg). (3) Frequency — Kisunla q4wk (13 doses/yr max); Leqembi q2wk (26 doses/yr). (4) Treatment duration — Kisunla can be discontinued at amyloid PET clearance (typically 6–18 months); Leqembi is given indefinitely. (5) MRI surveillance schedule — Kisunla pre-infusions 2, 3, 4, 7; Leqembi pre-infusions 5, 7, 14. (6) APOE4 homozygote ARIA incidence — Kisunla ~40%, Leqembi ~32%. Both require CMS CED registry enrollment and amyloid pathology confirmation. See side-by-side comparison.

When can I stop Kisunla treatment?

Kisunla's distinguishing feature: per the FDA label (full approval July 2024), donanemab can be discontinued when amyloid PET imaging shows clearance — typically after 6 to 18 months of therapy. This is a major billing implication. Unlike Leqembi (continued indefinitely), Kisunla has a finite expected treatment duration. Continued infusions after documented amyloid clearance will trigger payer audits and recoupment. Most payers require repeat amyloid PET at 12 months (some at 18 months) to assess whether to continue. Document the PET result before each maintenance phase decision.

Source documents

1. Kisunla HCP — Dosing & Administration
   Eli Lilly HCP coding & reimbursement page
2. DailyMed — KISUNLA (donanemab-azbt) Prescribing Information
   FDA-approved label, full approval July 2, 2024 (BLA 761248); most recent revision December 30, 2025 (adopts ascending Dosing Regimen 2: 350/700/1,050/1,400 mg)
3. FDA Kisunla label PDF (s000, 2024)
4. CMS NCD 210.20 — Monoclonal Antibodies Directed Against Amyloid for the Treatment of Alzheimer's Disease
   Coverage with Evidence Development (CED) requirement
5. ALZ-NET (Alzheimer's Network for Treatment and Diagnostics)
   CMS-approved CED registry; most-used for anti-amyloid mAb coverage
6. CMS — Medicare Part B Drug ASP Pricing File
   Q2 2026 quarterly file, effective April 1 – June 30, 2026
7. American Academy of Neurology — Clinical Guidance for Anti-Amyloid Therapy
8. UnitedHealthcare — Medical Drug Coverage Policy (anti-amyloid mAbs)
9. Aetna CPB — Anti-Amyloid Monoclonal Antibodies
10. FDA National Drug Code Directory
11. Lilly Patient One — Lilly Cares Foundation Patient Assistance Program

About this page

We maintain this page as a living reference. Medicare ASP pricing is bound to our underlying CareCost data layer and refreshes automatically when CMS publishes new quarterly files. Coding and policy content is reviewed at least quarterly and updated whenever a source document changes.

Found an error? Email hello@carecostestimate.com.

Refresh cadence

Reviewer

Change log

• May 23, 2026 — SME audit pass. Migrated all dosing references from the original 700/700/700/1,400 regimen to the current ascending 350/700/1,050/1,400 mg Regimen 2 (label rev Dec 30, 2025). Updated DailyMed setid to 190352d4-ef62-4679-b4fa-e846e2766afa. Per-dose unit counts, NDC volume references, and per-dose reimbursement examples recalculated. Pricing and HCPCS unchanged.
• May 2, 2026 — Initial publication. ASP data: Q2 2026. Manufacturer source: Lilly HCP coding (2026). FDA label: full approval July 2, 2024 (BLA 761248). HCPCS J0175 effective January 1, 2025 (2 mg per unit). CMS NCD 210.20 CED registry requirement noted. Cross-linked with /drugs/leqembi.

Methodology

Every claim on this page is sourced inline. Pricing reflects the current CMS Part B Drug ASP Pricing File. Payer policies are read directly from each payer's published medical/pharmacy policy documents. Indication, dosing, MRI schedule, ARIA incidence data, and discontinuation criteria are verified against the current FDA label revision and Lilly HCP materials. We do not paraphrase from billing-software vendor blogs.