Aldurazyme (laronidase) — HCPCS J1931
CareCost Estimate · Billing Cheat Sheet
BioMarin / Sanofi Genzyme
5 mg/5 mL single-dose vial
IV infusion 3–4 hr, weekly (lifelong)
Reviewed: May 2, 2026
ASP: Q2 2026
BOXED WARNING — Anaphylaxis. Severe and life-threatening hypersensitivity reactions, including anaphylaxis, observed during and up to 3 hours post-infusion. Premedicate with antihistamines (± antipyretics) ~60 min before each infusion. Administer in a healthcare setting with resuscitation equipment immediately available. Patients with compromised respiratory function or acute febrile/respiratory illness at higher risk.
HCPCS
J1931
1 unit = 0.1 mg
Adult dose
500 units
~50 mg (86 kg, 0.58 mg/kg) wkly
Modifier
JZ / JW
Wt-based → frequent waste
Admin CPT
96365
+96366 ×2–3 (3–4 hr infusion)
Medicare ASP+6%
$39.954
/0.1 mg · $19,977/50 mg dose
Codes & NDC
| HCPCS | J1931 — "Laronidase injection" (permanent; 1 unit = 0.1 mg) |
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| NDC | 58468-070-01 (10) / 58468-0070-01 (11) — N4 qualifier |
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| Vial | 5 mg / 5 mL (1 mg/mL) single-dose; refrigerate 2–8°C; do not freeze/shake |
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| FDA approval | Apr 30, 2003 (BLA 125058) — first MPS I ERT |
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| Benefit | Medical (provider buy-and-bill); rare-disease nurse case mgmt via Sanofi/BioMarin |
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Dosing & unit math
- 0.58 mg/kg IV once weekly, lifelong
- Infusion ~3–4 hr with slow titration; 1-hr observation post
- 52 weekly infusions/year
- Adult example: 86 kg × 0.58 = 50 mg = 500 units; 10 vials, no waste → JZ
- Pediatric example: 30 kg × 0.58 = 17.4 mg = 174 units administered + 26 units JW waste (4 vials drawn = 20 mg)
Administration & modifiers
| Code | When |
|---|
96365 | Therapeutic IV, 1st hour (primary) — non-chemo |
96366 | Each additional hour (×2–3 typical) |
96413 | Not appropriate — laronidase is non-chemo ERT |
JZ/JW required: One must be on every J1931 claim per CMS 7/1/2023 SDV policy. Weight-based dosing across 5 mg vials → frequent waste → JW line is the norm.
ICD-10 — MPS I subtypes only
| Code | For |
|---|
E76.01 | Hurler syndrome (severe) |
E76.02 | Hurler-Scheie (intermediate) |
E76.03 | Scheie syndrome (attenuated) |
E76.1 | NO — MPS II Hunter → Elaprase J1743 |
E76.2 / E76.29 | NO — other MPS → Naglazyme/Vimizim/Mepsevii |
Diagnostic confirmation required: α-L-iduronidase enzyme assay AND/OR IDUA gene testing in chart for PA approval.
MPS treatment landscape
| MPS | Brand | HCPCS |
|---|
| I (Hurler/Scheie) | Aldurazyme | J1931 |
| II (Hunter) | Elaprase | J1743 |
| IVA (Morquio A) | Vimizim | J1322 |
| VI (Maroteaux-Lamy) | Naglazyme | J1458 |
| VII (Sly) | Mepsevii | J3397 |
Cross-billing risk: J1931 + E76.1 (Hunter) will deny — wrong drug for the subtype. Always confirm enzyme deficiency from genetics workup.
Payer requirements (May 2026)
| Payer | PA | Key criteria |
|---|
| UnitedHealthcare | Yes | Confirmed MPS I + specialist consult + lifelong commitment |
| Aetna | Yes | Enzyme assay AND/OR IDUA testing; metabolic specialist Rx |
| BCBS plans | Yes | FDA label-aligned; specialist oversight |
| Medicare (LCDs) | No formal PA | FDA-approved MPS I indication; medical necessity documented |
No step therapy — Aldurazyme is the only FDA-approved ERT for MPS I. HSCT is not a payer "step" requirement.
Medicare reimbursement (Q2 2026)
| Field | Value |
|---|
| ASP + 6% | $39.954 / 0.1 mg unit (eff. 4/1 – 6/30/2026) |
| 50 mg adult dose | $19,977.00 (500 × $39.954) |
| Annual (52 wkly doses) | ~$1,038,804/yr per adult |
| 17.4 mg pediatric dose | ~$6,952 (174 × $39.954) + JW waste line |
Site of care
| Setting | POS | Notes |
|---|
| Specialist office | 11 | Preferred (commercial UM) |
| Ambulatory infusion suite | 49 | Preferred (commercial UM) |
| Hospital outpatient | 19/22 | OK early; UHC/Aetna steer out long-term |
| Patient home | 12 | Limited — boxed-warning anaphylaxis risk |
Patient assistance — Sanofi / BioMarin
- Sanofi Patient Connection: 1-866-906-6100
- Aldurazyme Patient Support / BioMarin RareConnections: dedicated rare-disease nurse case mgmt
- Commercial copay assistance (excludes Medicare/Medicaid/federal)
- PAP: free drug for uninsured/underinsured eligible
- Foundations (Medicare): PAN, HealthWell, NORD, National MPS Society
- Patient advocacy: mpssociety.org
Pending SME review. Staff-authored from FDA label, CMS Q2 2026 ASP, Sanofi/BioMarin materials, and major payer policies. Verify boxed-warning premedication protocol against current FDA label for high-stakes claims.