HCPCS
J1322
1 mg = 1 unit
Phase 1
Identify what you're billing
Confirm the right code, weight-based dose, and indication before billing.
About Vimizim & MPS IVA FDA verified Apr 2026
The only FDA-approved enzyme replacement therapy for Morquio A syndrome.
Vimizim (elosulfase alfa) is a recombinant human N-acetylgalactosamine-6-sulfatase (GALNS) enzyme, manufactured by BioMarin Pharmaceutical. It received FDA approval on February 14, 2014 (BLA 125460) as the first and only enzyme replacement therapy for mucopolysaccharidosis type IVA (MPS IVA), also known as Morquio A syndrome.
What is MPS IVA?
MPS IVA is an autosomal recessive lysosomal storage disorder caused by deficient activity of GALNS. The enzyme deficiency results in cellular accumulation of two glycosaminoglycans — keratan sulfate and chondroitin-6-sulfate — producing progressive multi-system disease: skeletal dysplasia (short stature, kyphoscoliosis, joint laxity), cardiac valve disease, restrictive and obstructive respiratory disease, corneal clouding, hearing loss, and cervical cord compression. MPS IVA is rare (estimated 1 in 200,000–300,000 live births).
Diagnostic workup payers expect
Most payers require documented diagnosis before approving J1322:
- Quantitative GALNS enzyme assay in leukocytes or fibroblasts demonstrating deficient activity
- Confirmatory GALNS gene mutation analysis (chromosome 16q24.3)
- Urine glycosaminoglycan (GAG) analysis showing elevated keratan sulfate
- Specialist consultation (geneticist, metabolic specialist, or pediatric endocrinologist)
Dosing & unit math FDA label Apr 2026
Weight-based, lifelong, weekly. From FDA prescribing information (BLA 125460).
Standard dose
- 2 mg/kg IV once weekly — same dose for adults and pediatric patients ≥5 years
- Lifelong therapy (52 doses/year typical, with infrequent missed doses for illness/travel)
- Infusion duration: ~3.5–4.5 hours total (initial slower rate ramped up if tolerated)
- Final infusion volume: 100 mL (patients <25 kg) or 250 mL (≥25 kg) of 0.9% NaCl
- 1 mg = 1 unit — bill (kg × 2) units per dose
Vial math — 5 mg single-dose vials
Vimizim ships in 5 mg/5 mL (1 mg/mL) single-dose vials. Weight-based dosing rarely lands on a clean 5-mg multiple, so most patients have partial-vial waste. The number of vials opened equals ceiling((kg × 2) / 5).
| Patient weight | Dose (mg) | Vials opened | Administered (units, JZ or JW) | Wasted (units, JW line) |
|---|---|---|---|---|
| 15 kg | 30 mg | 6 | 30 units | 0 (use JZ) |
| 20 kg | 40 mg | 8 | 40 units | 0 (use JZ) |
| 25 kg | 50 mg | 10 | 50 units | 0 (use JZ) |
| 30 kg | 60 mg | 12 | 60 units | 0 (use JZ) |
| 32 kg | 64 mg | 13 | 64 units | 1 unit (JW) |
| 38 kg | 76 mg | 16 | 76 units | 4 units (JW) |
| 45 kg | 90 mg | 18 | 90 units | 0 (use JZ) |
| 52 kg | 104 mg | 21 | 104 units | 1 unit (JW) |
| 60 kg | 120 mg | 24 | 120 units | 0 (use JZ) |
| 70 kg | 140 mg | 28 | 140 units | 0 (use JZ) |
Most weights = waste = JW required. Because dose is exactly 2 mg/kg and vials are 5 mg,
only weights divisible by 2.5 (15, 20, 25, 30, 35, 40, 45, 50, 60, 70 kg, etc.) result in zero waste.
Most adolescent and adult Morquio A patients fall into the JW category.
Worked example — first-year billing for a 30 kg pediatric patient
# Per-dose: 30 kg × 2 mg/kg = 60 mg = 60 units (12 vials, no waste)
Drug units billed per dose: 60 (J1322)
HCPCS: J1322 · Modifier: JZ · Vials: 12 × 5 mg
Admin: 96365 × 1 (first hour) + 96366 × 3 (hours 2–4)
# Year-1 totals
Total infusions: 52 (weekly)
Total drug units billed: 3,120 (52 × 60)
Total drug cost (Q2 2026 ASP+6%): ~$973,272 before sequestration
Drug units billed per dose: 60 (J1322)
HCPCS: J1322 · Modifier: JZ · Vials: 12 × 5 mg
Admin: 96365 × 1 (first hour) + 96366 × 3 (hours 2–4)
# Year-1 totals
Total infusions: 52 (weekly)
Total drug units billed: 3,120 (52 × 60)
Total drug cost (Q2 2026 ASP+6%): ~$973,272 before sequestration
NDC reference FDA NDC Directory verified May 2026
| NDC (10/11-digit) | Package | Use |
|---|---|---|
68135-020-01 / 68135-0020-01 |
5 mg / 5 mL (1 mg/mL) single-dose vial — 1 vial per carton | All weight-based doses (multiple vials per infusion) |
One vial size only. Unlike many specialty drugs, Vimizim ships in only the 5 mg/5 mL vial.
Make sure your pharmacy is opening the right number of vials for the patient's weight (ceiling((kg × 2) / 5))
and that the wasted portion is reported with the JW modifier on a separate claim line per CMS policy.
MPS treatment landscape — ERTs by subtype Verified May 2026
Each MPS subtype has its own distinct enzyme replacement therapy. ERTs are not interchangeable.
| Disease | Brand | HCPCS | Generic | Manufacturer | Deficient enzyme |
|---|---|---|---|---|---|
| MPS I (Hurler / Hurler-Scheie / Scheie) | Aldurazyme | J1931 |
laronidase | Sanofi Genzyme / BioMarin | α-L-iduronidase |
| MPS II (Hunter) | Elaprase | J1743 |
idursulfase | Takeda | iduronate-2-sulfatase |
| MPS III (Sanfilippo A/B/C/D) | No FDA-approved ERT | ||||
| MPS IVA (Morquio A) | Vimizim (this page) | J1322 |
elosulfase alfa | BioMarin Pharmaceutical | N-acetylgalactosamine-6-sulfatase (GALNS) |
| MPS IVB (Morquio B) | No FDA-approved ERT | ||||
| MPS VI (Maroteaux-Lamy) | Naglazyme | J1458 |
galsulfase | BioMarin Pharmaceutical | arylsulfatase B |
| MPS VII (Sly) | Mepsevii | J3397 |
vestronidase alfa-vjbk | Ultragenyx | β-glucuronidase |
BioMarin makes three of the six ERTs in this class — Vimizim (MPS IVA), Naglazyme (MPS VI),
and Aldurazyme (MPS I, comarketed with Sanofi). All require BioMarin RareConnections (1-866-906-6100) for patient
access support.
Phase 2
Code the claim
Therapeutic IV admin (NOT chemo). Long infusion = multiple additional-hour units.
Administration codes CPT verified May 2026
Vimizim is enzyme replacement, NOT chemotherapy. Use therapeutic IV admin codes.
| Code | Description | When to use |
|---|---|---|
96365 |
Intravenous infusion, for therapy/prophylaxis (specify substance or drug); initial, up to 1 hour | Primary code for Vimizim. Bill once per infusion encounter. |
96366 |
Intravenous infusion, for therapy/prophylaxis; each additional hour (up to 8 hours) | Bill 3 units typical for a 4-hour infusion (hours 2, 3, 4). Adjust per actual infusion duration documented. |
96367 / 96368 |
Sequential / concurrent IV infusion of additional substance | For premedications administered IV before/during the infusion (e.g., IV diphenhydramine). |
96413 / 96415 |
Chemotherapy administration, IV infusion | NOT appropriate. Vimizim is enzyme replacement, not chemo or immunotherapy. |
Document infusion start and stop times. Because Vimizim infusions are long (~3.5–4.5 hours)
and additional-hour units are billed in increments, accurate timekeeping is essential. Most commercial payers
and Medicare audit infusion-hour billing on long therapeutic infusions.
Post-infusion observation is clinically required but not separately billable in most settings.
Bundle observation time into the E/M or infusion-suite facility fee per your payer's policy.
Modifiers CMS verified May 2026
JW — required on most Vimizim claims (waste)
JW reports the discarded portion of a single-dose vial. Because Vimizim is dosed at 2 mg/kg into 5 mg vials, most patient weights produce partial-vial waste. The administered units go on the J1322 line; the wasted units go on a separate J1322 line with the JW modifier.
JZ — when no waste
Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. For Vimizim, JZ applies only to weights that are exact 2.5-kg multiples (e.g., 15, 20, 25, 30, 35, 40, 45, 50, 60, 70 kg). Every J1322 claim must carry either JZ or JW.
Common error: Forgetting to bill the discarded portion on weight-based doses. CMS audits
often catch this. Bill the JW line with the actual discarded units alongside the line for the units
administered. Wasted drug is reimbursable but must be reported.
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-infusion reaction assessment, treatment plan review with the metabolic specialist). Routine pre-infusion clinical assessment is bundled into the infusion code.
340B modifiers (JG, TB)
For 340B-acquired Vimizim, follow your MAC's current 340B modifier policy. BioMarin's billing guide does not provide 340B-specific instructions for J1322.
ICD-10-CM — Morquio syndrome family FY2026 verified May 2026
Vimizim is approved only for MPS IVA (Morquio A). Use the most specific code supported by enzyme assay and genetic testing.
| Code | Description | When to use |
|---|---|---|
E76.219 | Morquio syndrome, unspecified | Default primary. Use when MPS IVA confirmed but A vs B not specified in chart. |
E76.210 | Morquio A syndrome | Preferred primary. Use when GALNS deficiency is confirmed by enzyme assay and/or genetic testing. |
E76.211 | Morquio B syndrome | Vimizim NOT indicated — Morquio B is a β-galactosidase deficiency, not GALNS. |
E76.29 | Other mucopolysaccharidoses | Not appropriate for Vimizim PA. |
Supplementary codes for organ involvement
Most payers expect documentation of multi-system disease in the PA. Add supplementary codes as applicable:
| System | ICD-10 (examples) | Findings |
|---|---|---|
| Cardiovascular | I35.0, I35.1, I34.x | Aortic stenosis/regurgitation, mitral valve disease |
| Respiratory | J96.x, G47.33, J98.4 | Respiratory failure, OSA, restrictive lung disease |
| Musculoskeletal | M40.x, M41.x, M43.x, M19.x | Kyphosis, scoliosis, spondylolisthesis, joint laxity/arthropathy |
| Cervical / spinal cord | M48.0x, G95.x, M99.0x | Cervical spinal stenosis, myelopathy, segmental dysfunction |
| Ophthalmologic | H18.4x, H17.x | Corneal clouding, scarring |
| Hearing | H90.3, H90.5 | Sensorineural / mixed hearing loss |
| Growth / endocrine | R62.52, E34.3 | Short stature, growth retardation |
Diagnosis confirmation is non-negotiable. Most payers require enzyme assay (GALNS deficiency)
AND/OR confirmatory GALNS gene mutation analysis in the PA submission. ICD-10 alone is not sufficient.
Site of care & place of service Verified May 2026
Because Vimizim infusions are long (3.5–4.5 hours) and carry an anaphylaxis boxed warning, site-of-care decisions weigh chair time, observation capability, and emergency-response readiness. UnitedHealthcare, Aetna, and major BCBS plans typically allow Vimizim in any setting with appropriate emergency support but may steer ongoing therapy out of HOPD after early stabilization.
| Setting | POS | Claim form | Payer steering |
|---|---|---|---|
| Hospital outpatient (on-campus) | 22 | UB-04 / 837I | Common for first 6–12 doses (initial reaction risk window) |
| Hospital outpatient (off-campus PBD) | 19 | UB-04 / 837I | Acceptable; some commercial UM disfavors after early stabilization |
| Physician office (metabolic / genetics) | 11 | CMS-1500 / 837P | Acceptable if anaphylaxis-equipped |
| Ambulatory infusion suite (AIC) | 49 | CMS-1500 / 837P | Preferred by commercial UM after stabilization |
| Patient home (home infusion) | 12 | CMS-1500 (with home infusion) | Possible for stable, tolerant patients via specialty home-infusion vendor with anaphylaxis protocol; many payers require prior in-clinic tolerance period (e.g., 6–12 doses without reaction) |
Home infusion is feasible but conditional. Some payers permit home infusion for patients who have
tolerated multiple in-clinic doses without significant reactions. Verify the home-infusion vendor's anaphylaxis
protocol and emergency response capability is on file with the payer before billing.
Claim form field mapping BioMarin 2026
Reference: BioMarin RareConnections coding & billing materials.
| Information | CMS-1500 box | Notes |
|---|---|---|
| NPI | 17b | Rendering provider (typically metabolic specialist or infusion center) |
| NDC qualifier + 11-digit NDC + UoM + qty | 24A shaded area | N4 + 68135-0020-01 + ML + total mL administered (e.g., 60 mL for 60 mg) |
| HCPCS J1322 (administered units) + JZ or JW | 24D (drug line) | Administered units; JZ if no waste, JW if waste (most claims) |
| HCPCS J1322 + JW (wasted units, separate line) | 24D (waste line) | Discarded units when partial vial waste occurs |
| Drug units | 24G | Patient weight (kg) × 2 for the administered line; vial-rounded waste for the JW line |
| CPT 96365 (admin line, first hour) | 24D | Initial therapeutic IV infusion |
| CPT 96366 (admin line, additional hours) | 24D | Bill 3 units typical for 3.5–4.5 hr total infusion |
| ICD-10 | 21 | E76.210 (Morquio A) preferred when GALNS deficiency confirmed; E76.219 default |
| PA number | 23 | Required by all major payers for J1322 |
Phase 3
Get paid
Diagnosis confirmation + specialist letter + lifelong-therapy attestation drive PA approval.
Payer policy snapshot Reviewed May 2026
All major payers cover Vimizim for confirmed MPS IVA. PA criteria focus on diagnostic confirmation, specialist involvement, and clinical monitoring.
| Payer | PA? | Documentation expected | Site-of-care UM |
|---|---|---|---|
| UnitedHealthcare LSD ERT Policy |
Yes | GALNS enzyme assay (deficient activity) + GALNS gene mutation analysis + geneticist or metabolic specialist letter; baseline echo, PFTs, cervical MRI, ophthalmology, audiology | HOPD acceptable initially; AIC/office preferred for ongoing therapy |
| Aetna CPB / Medical Drug policies |
Yes | Confirmed MPS IVA diagnosis (enzyme + genetic) + specialist consultation; ongoing monitoring (6 min walk distance, PFTs, cardiac assessment) | Yes — site-of-care policy for long-term ERT favors AIC/office |
| BCBS plans Vary by plan |
Yes | Generally aligned with FDA label and AAP MPS guidelines; require diagnostic confirmation and specialist-led care | Plan-specific; most have ERT site-of-care steering |
| Cigna / Evernorth Coverage Policy |
Yes | Confirmed MPS IVA + specialist + clinical response review at 6–12 months | AIC/office preferred; HOPD allowed in early phase |
Continuation of therapy criteria
Most payers require periodic reassessment (typically every 6–12 months) to continue Vimizim coverage. Documentation expected: stable or improved 6-minute walk distance, pulmonary function, cardiac function, endurance / activities of daily living, and absence of severe infusion reactions necessitating discontinuation.
Step therapy
Not applicable. Vimizim is the only FDA-approved ERT for MPS IVA — there is no therapeutic alternative within the same drug class for this indication.
Medicare reimbursement CMS Q2 2026 (live)
Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.
Q2 2026 payment snapshot — J1322
Effective April 1 – June 30, 2026 · Based on 4Q25 ASP submissions
ASP + 6%
$311.946
per mg / per unit
60 mg dose (30 kg patient)
$18,716.76
60 units × ASP+6%
140 mg dose (70 kg patient)
$43,672.44
140 units × ASP+6%
Annualized cost (Medicare ASP+6%): 30 kg patient, 60 units × 52 weekly infusions =
~$973,272/year. 70 kg patient, 140 units × 52 weeks =
~$2,270,966/year. After ~2% sequestration, actual paid is roughly ASP + 4.3%.
Vimizim is among the highest-cost lifelong therapies in Medicare Part B.
Coverage
No NCD specific to elosulfase alfa. Coverage falls under MAC LCDs for lysosomal storage disorder enzyme replacement therapies and the generic Part B drug-coverage framework. All MACs cover J1322 for confirmed MPS IVA with appropriate diagnostic documentation. Lifelong therapy is the standard of care when tolerated.
Code history
- J1322 — permanent code, "Elosulfase alfa, injection," 1 mg per unit. Effective shortly after FDA approval (Feb 2014); pre-permanent-code period used unclassified J3490.
Patient assistance — BioMarin RareConnections BioMarin verified May 2026
- BioMarin RareConnections / Vimizim Patient Support: 1-866-906-6100 — benefits investigation, prior authorization assistance, appeal support, infusion logistics coordination
- Co-pay assistance: commercial copay program for eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients)
- Patient assistance program (PAP): free product for uninsured / underinsured patients meeting income requirements
- Foundations for Medicare patients: refer to PAN Foundation, HealthWell Foundation, NORD — verify open MPS IVA / lysosomal storage disorder funds quarterly (often closed; high demand)
- Travel / logistics support: RareConnections case managers coordinate infusion-center selection, scheduling, and lodging support for families traveling to specialty centers
- Web: vimizim.com / biomarin.com/patient-support
Need to model what a specific patient will actually pay after copay assistance, deductible, coinsurance,
and OOP max? Run a CareCost Estimate — J1322 pre-loaded.
Phase 4
Safety & infusion management
Anaphylaxis is the headline risk. Premedication and emergency readiness are non-negotiable.
Anaphylaxis — boxed warning FDA label verified Apr 2026
BOXED WARNING — ANAPHYLAXIS. Severe hypersensitivity reactions, including
anaphylaxis, have been observed in Vimizim-treated patients during and after Vimizim infusion. Closely
observe patients during and after the infusion and be prepared to manage anaphylaxis. Inform patients of
the signs and symptoms of anaphylaxis and have them seek immediate medical care should signs and symptoms occur.
Required at every infusion
- Healthcare professional administration in a setting with appropriate medical support
- Immediate access to epinephrine and resuscitation equipment
- Trained personnel able to recognize and treat anaphylaxis
- Pre-infusion premedication (antihistamines ± antipyretics; add corticosteroids for prior reactions) — see premedication protocol
- Post-infusion observation period (duration per institutional protocol; longer for new patients or prior reactors)
Reaction management algorithm (per FDA label)
- Mild reactions (e.g., mild pyrexia, urticaria): slow or temporarily interrupt infusion; consider additional antihistamine
- Moderate reactions (e.g., bronchospasm, hypotension, angioedema): interrupt infusion; treat symptomatically; may resume at slower rate after resolution if clinically appropriate
- Severe reactions / anaphylaxis: immediately discontinue infusion; administer epinephrine; provide supportive care (oxygen, fluids, advanced airway as needed); permanent discontinuation should be considered
Special populations — cervical spinal cord compression
Cervical spinal cord compression is common in MPS IVA and may be exacerbated by infusion-related neurological symptoms. Patients with significant cervical spine instability or cord compression require specialist evaluation before initiating Vimizim. Anaphylaxis with hypotension and respiratory compromise carries added risk in this population.
Premedication protocol FDA label verified Apr 2026
Premedication is required before every Vimizim infusion. Confirm administration in the chart
and code as appropriate (CPT 96367 for sequential IV; J-codes for IV antihistamines/steroids).
Standard premedication (every infusion)
- Antihistamine (e.g., diphenhydramine PO/IV, cetirizine PO) — 30–60 minutes pre-infusion
- Antipyretic (e.g., acetaminophen PO) — 30–60 minutes pre-infusion (with or without antihistamine per institutional protocol)
Enhanced premedication (patients with prior infusion reactions)
- Standard premedication above, PLUS:
- Corticosteroid (e.g., methylprednisolone IV, hydrocortisone IV) — 30–60 minutes pre-infusion
- Consider slowing infusion rate at re-introduction
- Specialist consultation regarding desensitization or discontinuation if reactions persist
Premedication checklist
- ☐ Antihistamine ordered and administered 30–60 min pre-infusion (PO or IV)
- ☐ Antipyretic ordered and administered 30–60 min pre-infusion (per protocol)
- ☐ Corticosteroid added if prior reaction history (with documentation in chart)
- ☐ Epinephrine + resuscitation equipment present at chairside, checked, in date
- ☐ Patient/caregiver counseled on anaphylaxis symptoms and 911/ED instructions
- ☐ Baseline vitals documented; vitals every 15–30 min during infusion per protocol
- ☐ Post-infusion observation period completed and documented before discharge
Common denials & how to fix them
| Denial reason | Common cause | Fix |
|---|---|---|
| Diagnosis not confirmed | PA submitted without GALNS enzyme assay or genetic confirmation | Submit enzyme assay result + GALNS gene mutation analysis + specialist letter. Schedule diagnostic workup BEFORE submitting PA. |
| JW missing on weight-based dose | Wasted drug not reported on partial-vial-waste dose | Add JW line for discarded units. Administered units on the primary line; wasted units on a separate line with JW. |
| JZ missing on no-waste claim | Single-dose vial claim without JZ when no waste occurred | Resubmit with JZ. Required since 7/1/2023 on every claim with no waste. |
| Wrong admin code (96413) | Chemotherapy IV billed instead of therapeutic IV | Resubmit with 96365 + 96366. Vimizim is enzyme replacement, not chemo or immunotherapy. |
| Insufficient additional-hour units (96366) | 96366 billed only for 1 additional hour on a 4-hour infusion | Bill 96365 × 1 + 96366 for each additional full hour beyond hour 1. Document infusion start/stop times. |
| Wrong ICD-10 (E76.211) | Morquio B coded for Vimizim claim | Vimizim is for MPS IVA only. Resubmit with E76.210 (Morquio A) when GALNS deficiency confirmed; E76.219 default. |
| Specialist not involved | PA submitted by primary care without geneticist / metabolic specialist consultation | Add specialist consultation note to PA. Most payers require involvement of a metabolic specialist, geneticist, or pediatric endocrinologist. |
| Continuation denied at 6/12 mo | Reauthorization without ongoing-benefit documentation | Submit clinical reassessment: 6 min walk distance, PFTs, cardiac function, ADL status. Include any infusion reaction history. |
Frequently asked questions
What is the HCPCS code for Vimizim?
Vimizim (elosulfase alfa) is billed under HCPCS J1322 — "Elosulfase alfa, injection."
Each milligram equals one billable unit. Vimizim is the only FDA-approved enzyme replacement therapy for
mucopolysaccharidosis type IVA (MPS IVA / Morquio A syndrome).
How many units do I bill for a Vimizim dose?
Bill (patient weight in kg) × 2 units per weekly infusion. A 30 kg patient
receives 60 mg = 60 units. Vimizim ships in 5 mg single-dose vials, so weight-based dosing typically
creates partial-vial waste — bill the discarded amount with the JW modifier on a
separate claim line.
What administration CPT do I use for Vimizim?
CPT 96365 for the first hour of therapeutic IV infusion (non-chemotherapy) plus CPT
96366 for each additional hour. Vimizim infusion duration is approximately
3.5–4.5 hours total — expect to bill 96365 × 1 + 96366 × 3. Do NOT bill chemotherapy
admin codes (96413/96415) — Vimizim is enzyme replacement, not chemo or immunotherapy.
Does Vimizim have a boxed warning?
Yes. Vimizim carries a BOXED WARNING for anaphylaxis. Severe hypersensitivity reactions, including anaphylaxis, have been observed during and after Vimizim infusion. Administer in a healthcare setting with epinephrine and resuscitation equipment immediately available. Premedication with antihistamines (with or without antipyretics) 30–60 minutes before infusion is required. Patients require post-infusion observation. Patients with prior infusion reactions may also need pre-infusion corticosteroids.
Do I bill JZ or JW for Vimizim?
Both modifiers apply depending on the dose. Vimizim ships in 5 mg single-dose vials and dosing is
2 mg/kg weekly — so most patient weights produce partial-vial waste (use JW). Weights
that are exact 2.5-kg multiples (e.g., 25, 30, 45, 60 kg) result in zero waste (use JZ).
Per CMS's July 2023 policy, every J1322 claim must carry either JZ or JW.
What is the Medicare reimbursement for J1322?
For Q2 2026, the Medicare Part B payment limit for J1322 is $311.946 per mg (ASP + 6%). For a 30 kg patient (60 mg dose), the drug reimbursement is approximately $18,716.76 per weekly infusion. Annualized cost (Medicare ASP+6%): approximately $973,272/year for a 30 kg patient receiving 52 weekly infusions. Vimizim is one of the highest-cost lifelong therapies in Medicare Part B. Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.
What ICD-10 codes apply to Vimizim?
Primary: E76.219 (Morquio syndrome unspecified) when MPS IVA confirmed but A/B not specified.
Preferred: E76.210 (Morquio A) when GALNS deficiency is confirmed by enzyme
assay and/or GALNS gene mutation analysis. Add supplementary codes for organ involvement (cardiac valve
disease, scoliosis/kyphosis, OSA / restrictive lung disease, corneal clouding) as applicable. E76.211
(Morquio B) is NOT covered by Vimizim — Morquio B is β-galactosidase deficiency, not GALNS.
Which other MPS enzyme replacement therapies are similar to Vimizim?
Each MPS subtype has its own distinct ERT — not interchangeable. Aldurazyme (J1931 laronidase) treats MPS I. Elaprase (J1743 idursulfase) treats MPS II (Hunter). Vimizim (J1322) treats MPS IVA only. Naglazyme (J1458 galsulfase) treats MPS VI (Maroteaux-Lamy). Mepsevii (J3397 vestronidase alfa-vjbk) treats MPS VII (Sly). MPS III (Sanfilippo) and MPS IVB have no FDA-approved ERT.
Reference
Sources & methodology
Every claim on this page is sourced. Methodology and review history below.
Source documents
- DailyMed — VIMIZIM (elosulfase alfa) Prescribing Information
- FDA Drugs@FDA — Vimizim label PDF
- CMS — Medicare Part B Drug ASP Pricing File
- BioMarin Pharmaceutical — Vimizim product page
- Vimizim.com — HCP coding, coverage, and patient support resources
- SEER CanMED — HCPCS J1322 reference
- American Academy of Pediatrics — Mucopolysaccharidosis health supervision and management guidelines
- UnitedHealthcare — Lysosomal Storage Disorder Enzyme Replacement Therapy Medical Drug Policy
- Aetna — Mucopolysaccharidosis Treatment CPB / Medical Drug policies
- FDA National Drug Code Directory
- National Organization for Rare Disorders (NORD) — Morquio syndrome reference
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
| Element | Cadence | How it's refreshed |
|---|---|---|
| Medicare ASP pricing | Quarterly | Auto-bound to CareCost ASP layer; updates on CMS file release. |
| Payer policies (UHC, Aetna, BCBS, Cigna) | Semi-annual | Manual review against published payer policy documents. |
| HCPCS / CPT / modifier rules | Annual | Reviewed against CMS HCPCS quarterly files, AMA CPT releases. |
| NDC, dosing, FDA label, boxed warning | Event-driven | Tied to BioMarin document version + FDA label revision date. |
Pending SME review. This page is staff-authored from primary sources (FDA, CMS, BioMarin,
payer documents — all linked above). Editorial review in progress.
Until that review is complete, treat this as a draft reference and verify each cited source for high-stakes claims.
Change log
- — Initial publication. ASP data: Q2 2026. Manufacturer source: BioMarin RareConnections / Vimizim.com (verified May 2026). FDA label: verified April 2026 (BLA 125460). Boxed warning: anaphylaxis. MPS treatment landscape table includes Aldurazyme (J1931), Elaprase (J1743), Naglazyme (J1458), Mepsevii (J3397).
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 and safety content (including boxed warning) is verified against the current FDA label revision. We do not paraphrase from billing-software vendor blogs.