Cerezyme (imiglucerase) — HCPCS J1786

Gaucher disease treatment landscape Verified May 2026

Cerezyme is the original glucocerebrosidase ERT (FDA 1994). Two newer IV ERTs and two oral substrate reduction therapies (SRT) compete for the same patient population.

Type 1 Gaucher disease (the most common form, >90% of cases) is treated either by replacing the deficient enzyme (ERT, IV, medical benefit) or by reducing substrate accumulation (SRT, oral, pharmacy benefit). All three IV ERTs target the same enzyme deficiency; choice is typically driven by payer formulary, infusion-center logistics, and (rarely) immunogenicity history.

For other lysosomal storage disorders with recombinant ERTs, see CareCost references (when available): Aldurazyme (laronidase, MPS I) and Fabrazyme (agalsidase beta, Fabry disease).

Brand interchangeability & payer formulary management Verified May 2026

Three brand IV ERTs, one disease, payer-driven brand selection.

While Cerezyme, VPRIV, and Elelyso are not legally interchangeable at the pharmacy or claim level (each has its own NDC and HCPCS), payers manage them as a therapeutic class for formulary purposes. Switching between brands is clinically straightforward but requires a separate prior authorization and a new claim line under the new HCPCS.

Dosing & unit math FDA label verified 2025

From FDA prescribing information (BLA 103573).

Adult & pediatric Type 1 Gaucher (most common)

• 60 IU/kg IV every 2 weeks — most common starting dose; 26 doses/year
• 2.5 IU/kg IV three times per week — alternative (older) regimen; ~156 doses/year
• Dose individualized based on hemoglobin, platelet count, hepatic and splenic volume, bone disease, and biomarker response (chitotriosidase, glucosylsphingosine / lyso-Gb1)
• Maintenance dose may be reduced (e.g., to 30–45 IU/kg q2w) once therapeutic goals achieved

Type 3 (chronic neuronopathic) Gaucher

• Per specialist guidance — ERT addresses systemic disease; CNS involvement is not penetrated by IV ERT
• Dosing typically at the upper end of the Type 1 range

Unit math — the 10 IU billing unit

1 J1786 billing unit = 10 IU (units) of imiglucerase. Always divide the total IU administered by 10 before entering the unit count on the claim. Pediatric and low-weight adult doses will produce small unit counts; high-weight adult doses produce large counts. Both are normal.

Worked example — standard adult dose (70 kg patient, 60 IU/kg q2w)

Worked example — pediatric (25 kg child, 60 IU/kg q2w)

NDC reference FDA NDC Directory verified May 2026

Administration codes CPT verified May 2026

Cerezyme is non-chemo enzyme replacement therapy — therapeutic IV codes only.

Modifiers CMS verified May 2026

JZ + JW — both apply on virtually every claim

Cerezyme is uniquely vulnerable to fixed-vial waste: only one vial size (400 IU) exists, but dosing is weight-based. A 70 kg patient at 60 IU/kg needs 4,200 IU but must draw 11 vials (4,400 IU), leaving 200 IU of waste. Bill JW with the discarded units on a separate claim line, AND JZ on the administered units per CMS's July 2023 single-dose container policy.

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. Routine pre-infusion clinical assessment is bundled into the infusion service.

340B modifiers (JG, TB)

For 340B-acquired Cerezyme, follow your MAC's current 340B modifier policy. Sanofi's billing guide does not provide 340B-specific instructions; defer to MAC LCD and your hospital's 340B compliance team.

ICD-10-CM diagnosis coding FY2026 verified May 2026

E75.22 is the primary anchor; supplementary codes document organ-system findings supporting medical necessity.

Site of care & place of service Verified May 2026

Major commercial payers run aggressive site-of-care utilization management on lysosomal storage disorder ERTs. Stable Cerezyme patients are routinely steered out of HOPD into office, ambulatory infusion suite, or home infusion settings.

Claim form field mapping Sanofi Patient Connection 2025

From Sanofi Cerezyme reimbursement guide (Sanofi Patient Connection HCP materials).

Payer policy snapshot Reviewed May 2026

All major payers gate Cerezyme behind diagnostic confirmation and specialist consultation. Brand selection within the ERT class is increasingly formulary-driven.

Step therapy

Step therapy within the ERT class (e.g., requiring VPRIV or Elelyso failure before Cerezyme) is uncommon but plan-specific. Step therapy from oral SRT (Cerdelga) into IV ERT is generally not required — ERT remains the standard of care for newly diagnosed Type 1 Gaucher.

Reauthorization

Annual reauthorization is the norm. Submit current Hgb, platelet count, hepatic and splenic volumes (typically by MRI or CT), bone disease assessment, and biomarker trend (chitotriosidase or glucosylsphingosine). Documented stability or improvement on therapy supports continued coverage.

Medicare reimbursement CMS Q2 2026 (live)

Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.

Coverage

Cerezyme is covered by all MACs under their generic Part B drug-coverage framework with appropriate E75.22 + diagnostic documentation. No NCD specific to imiglucerase. Local MAC LCDs may exist for lysosomal storage disorder ERTs; verify per jurisdiction.

Code history

• J1786 — permanent code, descriptor "Imiglucerase injection, 10 units"; in use since the late 1990s shortly after FDA approval (May 1994)

Patient assistance — Sanofi Patient Connection Sanofi verified May 2026

• Sanofi Patient Connection: 1-800-745-4447 — benefits investigation, prior authorization assistance, appeal support, copay program enrollment, free-drug program for eligible patients
• Cerezyme Patient Support: dedicated case management for Gaucher patients on Cerezyme; coordinates home infusion, specialty pharmacy, and patient education
• Commercial copay assistance: available for eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients)
• Patient assistance program (PAP): free product for uninsured / underinsured patients meeting income criteria
• Foundations (Medicare patients): National Gaucher Foundation, PAN Foundation (verify open lysosomal storage disease funds quarterly), HealthWell Foundation
• Web: sanofipatientconnection.com

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Cerezyme?

Cerezyme (imiglucerase) is billed under HCPCS J1786 — "Imiglucerase injection." One billing unit equals 10 IU (units), NOT 1 IU. This is the most common biller error: a 4,200 IU dose is billed as 420 units, not 4,200 units. J1786 has been a permanent code for decades and is the reference HCPCS for imiglucerase.

How many units do I bill for a 60 IU/kg Cerezyme dose?

Divide total IU administered by 10. A 70 kg patient at 60 IU/kg every 2 weeks receives 4,200 IU per dose, billed as 420 units of J1786. The 11 × 400 IU vials needed (4,400 IU total) leave 200 IU of waste billable on a separate JW line as 20 units. Always verify the patient's dosing strategy first — 60 IU/kg q2w (most common) and 2.5 IU/kg three times weekly are both FDA-labeled regimens with very different per-dose unit counts.

What administration CPT do I use for Cerezyme?

96365 (initial therapeutic IV infusion, up to 1 hour) plus 96366 (each additional hour) for the standard 1–2 hour Cerezyme infusion. Imiglucerase is enzyme replacement therapy (not chemotherapy), so the chemo administration codes (96413/96415) are NOT appropriate.

Do I bill JZ or JW for Cerezyme?

Both apply on most claims. Cerezyme comes only as a 400 IU single-dose vial, and dosing is weight-based — virtually every dose produces partial-vial waste. Bill JW with the discarded units on a separate claim line, AND JZ on the administered units. Per CMS's July 2023 single-dose container policy, every J1786 claim must carry one of JZ or JW.

What is the Medicare reimbursement for J1786?

For Q2 2026, the Medicare Part B payment limit for J1786 is $42.825 per billing unit (10 IU) under ASP + 6%. A 60 IU/kg dose for a 70 kg patient (4,200 IU = 420 units) reimburses at approximately $17,986.50 per infusion, or roughly $467,649/year on a q2w schedule (26 doses). Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.

What ICD-10 code is used for Gaucher disease?

E75.22 — "Gaucher disease" — is the primary ICD-10 code for all Cerezyme claims. Add supplementary codes as appropriate: D69.6 (thrombocytopenia), D64.9 (anemia), K76.89 (hepatosplenomegaly / other liver disease), M89.9 (skeletal disease). Diagnosis must be confirmed by acid β-glucosidase enzyme assay AND GBA gene mutation analysis to satisfy payer PA.

How does Cerezyme compare to VPRIV and Elelyso?

All three are recombinant human glucocerebrosidase ERTs for Type 1 Gaucher disease, given as IV infusions every 2 weeks at clinically equivalent doses (60 IU/kg q2w). Cerezyme (J1786, Sanofi Genzyme, FDA 1994) is the original. VPRIV (J3385, Takeda, FDA 2010) and Elelyso (J3060, Pfizer, FDA 2012) are newer entrants. Each carries its own HCPCS code, NDC, and ASP — they are not pharmacy-level interchangeable, but payers may mandate a specific brand under formulary management. Oral substrate reduction therapies Cerdelga (eliglustat) and Zavesca (miglustat) are alternative classes filled under the pharmacy benefit.

Does Cerezyme have a Boxed Warning?

No. Cerezyme has no Boxed Warning. Warnings & Precautions cover hypersensitivity reactions, antibody formation (~15% of patients develop IgG antibodies to imiglucerase, which may reduce efficacy), and rare pulmonary hypertension. Manage infusion reactions with rate reduction and pretreatment per FDA label; persistent inhibitor antibodies may require switching to an alternative ERT or oral SRT.

Source documents

1. DailyMed — CEREZYME (imiglucerase) Prescribing Information
   FDA-approved label (BLA 103573, May 1994); current revision
2. Sanofi Patient Connection — Cerezyme HCP reimbursement & coverage materials
   Patient enrollment, free-drug program, copay assistance, BI/PA support: 1-800-745-4447
3. CMS — Medicare Part B Drug ASP Pricing File
   Q2 2026 quarterly file, effective April 1 – June 30, 2026
4. SEER CanMED — HCPCS J1786 reference
   Permanent code descriptor: "Imiglucerase injection, 10 units"
5. UnitedHealthcare — Lysosomal Storage Disorder ERT medical drug policy
6. Aetna CPB — Enzyme Replacement Therapy for Gaucher Disease
7. Sanofi GaucherCare HCP portal
8. National Gaucher Foundation — clinician resources
9. FDA National Drug Code Directory
10. ASH / MGCC consensus guidance — Gaucher disease management

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 2, 2026 — Initial publication. ASP data: Q2 2026 ($42.825/billing unit). Manufacturer source: Sanofi Patient Connection 2025. FDA label: current 2025 revision (BLA 103573). Includes Gaucher class comparison (Cerezyme/VPRIV/Elelyso + oral SRT) and brand interchangeability guidance.

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. Diagnostic and dosing criteria reference the FDA label, ICGG Gaucher Registry data, and ASH/MGCC consensus guidance. We do not paraphrase from billing-software vendor blogs.