HCPCS
J2508
1 mg = 1 unit
Phase 1
Identify what you're billing
Confirm the right Fabry therapy, dose, vial math, and premedication protocol.
Fabry disease therapy class comparison FDA verified May 2026
Three FDA-approved options in the US. Replagal (agalsidase alfa) is approved in Europe but NOT in the US.
Three therapies are FDA-approved for Fabry disease, with very different billing infrastructure. Elfabrio is the newest (2023) and the first PEGylated α-Gal A ERT. Confirm the right comparator before quoting Elfabrio to a patient or payer — many payers run combined Fabry policies.
| Elfabrio | Fabrazyme | Galafold | |
|---|---|---|---|
| Generic | pegunigalsidase alfa-iwxj | agalsidase beta | migalastat |
| Mechanism | PEGylated recombinant α-Gal A ERT | Recombinant α-Gal A ERT | Pharmacological chaperone (oral) |
| HCPCS | J2508 | J0180 | None — pharmacy benefit |
| Manufacturer | Chiesi (US) / Protalix BioTherapeutics | Sanofi Genzyme | Amicus Therapeutics |
| FDA approval | May 2023 (BLA 761161) | April 2003 (BLA 103979) | August 2018 |
| Route & schedule | IV q2wk, 1 mg/kg, 3–4 hr initial / 2–3 hr maintenance | IV q2wk, 1 mg/kg, 2–4 hr initial | Oral 123 mg every other day |
| Patient eligibility | Any GLA mutation | Any GLA mutation | Amenable GLA missense mutations only (~30–50% of patients per FDA-validated assay) |
| Antibody formation | Designed for reduced antibody response (PEGylation) | Common (most seroconvert within 3–6 mo) | Not applicable (small molecule) |
| Pediatric | Adult only (no pediatric labeling as of May 2026) | Yes (≥2 yr per 2018 expansion) | Adult only |
| Vial | 20 mg/10 mL liquid (no reconstitution) | 5 mg + 35 mg lyophilized (reconstitute) | Capsule (oral) |
| Q2 2026 ASP+6% per mg | ~$223.40 | ~$227.58 | Pharmacy WAC |
| Benefit | Medical (provider buy-and-bill) | Medical (provider buy-and-bill) | Pharmacy |
Cross-references: For other lysosomal storage disorder ERTs, see
Aldurazyme (laronidase, MPS I),
Cerezyme (imiglucerase, Gaucher type 1), and
Elaprase (idursulfase, MPS II) — same infusion-center workflow,
different enzyme target.
Replagal (agalsidase alfa) is NOT FDA-approved. Replagal is approved in Europe and many
other regions but failed FDA approval in the US. Do not bill Replagal in the US — if a patient
presents on Replagal from abroad, switch to Elfabrio or Fabrazyme domestically and document the
formulary change.
Elfabrio vs Fabrazyme — side-by-side Manufacturer + FDA verified May 2026
Same molecule class, same dose, same schedule. Three meaningful differences for billing and three for clinical.
Elfabrio entered the US market in 2023 as the first new α-Gal A ERT in two decades. Many infusion centers now run both products side-by-side, with payer steering driven by contracted price rather than head-to-head efficacy. Use the table below to translate the differences into billing decisions before submitting prior auth.
| Elfabrio (J2508) | Fabrazyme (J0180) | |
|---|---|---|
| Approval year | 2023 | 2003 |
| Generic name | pegunigalsidase alfa-iwxj | agalsidase beta |
| Molecular design | PEGylated recombinant α-Gal A — PEG conjugation extends half-life and is designed to reduce immunogenicity | Non-PEGylated recombinant α-Gal A |
| Antibody / immunogenicity | Designed for reduced anti-drug antibody formation; long-term real-world data still accruing | Most patients seroconvert (develop IgG anti-agalsidase beta antibodies) within 3–6 months; titers can affect efficacy and IAR risk |
| Indication | Adult Fabry disease only | Adult + pediatric ≥2 years (2018 labeling expansion) |
| Dose / schedule | 1 mg/kg IV q2wk (lifelong) | 1 mg/kg IV q2wk (lifelong) |
| Initial infusion duration | ~3–4 hours | 2–4 hours (max rate 0.25 mg/min) |
| Maintenance infusion duration | ~2–3 hours in tolerant patients | ~2–4 hours; rate may be increased after tolerability |
| Vial format | 20 mg / 10 mL liquid single-dose vial — no reconstitution | 5 mg and 35 mg lyophilized — reconstitute with sterile water |
| Premedication | Recommended (acetaminophen + diphenhydramine ± corticosteroid) | Recommended (acetaminophen + diphenhydramine ± corticosteroid) |
| Boxed warning | None (W&P: anaphylaxis, IARs, MPGN, embryo-fetal toxicity) | None (W&P: anaphylaxis, IARs, antibody formation, embryo-fetal toxicity) |
| HCPCS | J2508 — "Pegunigalsidase alfa-iwxj" (1 mg = 1 unit) | J0180 — "Injection, agalsidase beta, 1 mg" (1 mg = 1 unit) |
| Q2 2026 ASP+6% per mg | ~$223.40 | ~$227.58 |
| Annual cost (70 kg adult, q2wk) | ~$406,588 (26 doses × $15,638) | ~$414,196 (26 doses × $15,930) |
| Manufacturer support | Chiesi Total Care — 1-833-444-FABRY (1-833-444-3227) | Sanofi Patient Connection — 1-866-906-6100 |
Why payers care about PEGylation: A material fraction of Fabrazyme patients develop
IgG anti-agalsidase beta antibodies, and high titers correlate with reduced clinical response and
higher infusion-associated reaction (IAR) rates. Elfabrio's PEGylation is designed to mitigate this.
For payers, the practical implication is a clinical pathway from Fabrazyme to Elfabrio for patients
with documented high titers or persistent IARs — a documented switch is far easier to PA than
a treatment-naïve Elfabrio start when Fabrazyme is the contracted preferred ERT.
Pediatric scope is the cleanest functional difference. If the patient is <18 years
old, Elfabrio is not labeled and the PA will be denied for off-label use. Use Fabrazyme (≥2 yr label)
or, if amenable mutation, Galafold (adult only). Re-check Elfabrio pediatric status at PA submission —
Chiesi has signaled pediatric development as a future indication.
Dosing & vial math FDA label verified May 2026
From the FDA Elfabrio prescribing information (BLA 761161, approved May 2023). Verify against Chiesi Total Care for current packaging.
Standard dosing
- 1 mg/kg IV every 2 weeks (lifelong) — adult Fabry disease only
- Initial infusion: ~3–4 hours per Chiesi protocol
- Subsequent infusions: ~2–3 hours in tolerant patients (rate may be increased after tolerability is established)
- 1 mg = 1 unit — bill the actual mg administered + JW for any discarded mg
- Typical adult: 26 doses/year (q2wk × 52 weeks)
- Pediatric: not FDA-approved as of May 2026 — use Fabrazyme for ages ≥2 years
Vial math — why JW is the rule
Elfabrio ships in fixed 20 mg / 10 mL liquid single-dose vials. Dosing is weight-based (1 mg/kg). Unless the patient's weight produces a dose that is an exact multiple of 20 mg, partial-vial waste will occur. Pre-build a per-weight cheat sheet for your infusion suite to standardize the JW line.
| Patient weight | Dose (1 mg/kg) | Vials drawn (20 mg ea.) | mg drawn | mg administered | mg discarded (JW) |
|---|---|---|---|---|---|
| 50 kg | 50 mg | 3 | 60 | 50 | 10 (bill JW) |
| 60 kg | 60 mg | 3 | 60 | 60 | 0 (bill JZ) |
| 67 kg | 67 mg | 4 | 80 | 67 | 13 (bill JW) |
| 70 kg | 70 mg | 4 | 80 | 70 | 10 (bill JW) |
| 78 kg | 78 mg | 4 | 80 | 78 | 2 (bill JW) |
| 80 kg | 80 mg | 4 | 80 | 80 | 0 (bill JZ) |
| 92 kg | 92 mg | 5 | 100 | 92 | 8 (bill JW) |
| 100 kg | 100 mg | 5 | 100 | 100 | 0 (bill JZ) |
Worked example — first-year billing for a 70 kg adult Fabry patient
# Standard adult, 70 kg, 1 mg/kg q2wk
Drug units administered per dose: 70 (J2508)
Drug units discarded per dose: 10 (J2508 with JW)
HCPCS: J2508 · Modifier: JW on waste line, no JZ needed when JW is on claim
Vials drawn: 4 × 20 mg = 80 mg total
Admin: 96365 (initial hour) + 96366 × 2–3 (additional hours, 3–4 hr initial infusion)
# Year-1 totals (initial year, includes longer initial infusions)
Total doses: 26 (q2wk)
Total drug units administered: 1,820 (26 × 70)
Total drug units discarded: 260 (26 × 10)
Total drug cost (Q2 2026 ASP+6%): ~$464,672 before sequestration
(admin + waste reimbursed together: 26 × 80 × $223.40)
# Same patient at exact-multiple weight (e.g., 80 kg)
Per dose: 80 units administered, 0 waste → bill J2508 × 80 with JZ
Annual: ~$464,672 (same total, no JW line needed)
Drug units administered per dose: 70 (J2508)
Drug units discarded per dose: 10 (J2508 with JW)
HCPCS: J2508 · Modifier: JW on waste line, no JZ needed when JW is on claim
Vials drawn: 4 × 20 mg = 80 mg total
Admin: 96365 (initial hour) + 96366 × 2–3 (additional hours, 3–4 hr initial infusion)
# Year-1 totals (initial year, includes longer initial infusions)
Total doses: 26 (q2wk)
Total drug units administered: 1,820 (26 × 70)
Total drug units discarded: 260 (26 × 10)
Total drug cost (Q2 2026 ASP+6%): ~$464,672 before sequestration
(admin + waste reimbursed together: 26 × 80 × $223.40)
# Same patient at exact-multiple weight (e.g., 80 kg)
Per dose: 80 units administered, 0 waste → bill J2508 × 80 with JZ
Annual: ~$464,672 (same total, no JW line needed)
Reconciliation discipline: The chart must show vial NDC, lot, vials drawn, mg
administered, and mg discarded for every infusion. Audits commonly catch one of three errors:
(1) JW omitted when waste occurred, (2) JZ used when waste actually occurred, (3) total billed
mg (admin + waste) exceeds total mg drawn from vials. Use the vial-math table above to pre-build
a per-weight cheat sheet for the infusion suite.
Premedication protocol Standard of care May 2026
Not formally required by FDA label but routinely used to mitigate infusion-associated reactions and hypersensitivity.
Hypersensitivity reactions including anaphylaxis can occur during Elfabrio infusion and up to 3 days post-infusion per the FDA label. Infusion-associated reactions (IARs) including chills, fever, headache, fatigue, nausea, paresthesia, and pruritus are reported. Premedication is standard of care in most US infusion centers, mirroring the Fabrazyme protocol.
| Premedication | Typical dose | Timing | Notes |
|---|---|---|---|
| Acetaminophen | 650–1000 mg PO | 30–60 min pre-infusion | Antipyretic; standard component |
| Diphenhydramine | 25–50 mg PO or IV | 30–60 min pre-infusion | H1 antihistamine; reduces hypersensitivity |
| Methylprednisolone (or equivalent) | 20–100 mg IV | 30–60 min pre-infusion | Optional; reserve for patients with prior IARs or treatment-naïve initiation |
| H2 blocker (e.g., famotidine) | 20–40 mg IV | 30–60 min pre-infusion | Some centers add for additional IAR mitigation |
Bill premedication separately under the appropriate J-code (e.g., J7050/J7042 for
IV solvent, J1200 for diphenhydramine 50 mg, J2920/J2930 for methylprednisolone) plus the additional
push or short-infusion CPT (96374 for IV push, 96375 for each additional sequential push). Acetaminophen
PO is not separately billable.
Document premedication and post-infusion observation. The 3-day post-infusion
anaphylaxis window in the FDA label is meaningful for site-of-care and home-infusion decisions.
Many centers schedule an additional 1-hour observation post-infusion for the first several
treatments. Standardize the order set so documentation is consistent across infusion days.
Hypersensitivity / anaphylaxis risk. Administer in a healthcare setting with
appropriate medical support and resuscitation equipment immediately available. Hypersensitivity
reactions including anaphylaxis have been reported during infusion and up to 3 days post-infusion
in clinical trials.
NDC reference FDA NDC Directory verified May 2026
| Package | Vial format | Use |
|---|---|---|
| 20 mg / 10 mL single-dose vial | Liquid (2 mg/mL); no reconstitution; refrigerate 2–8°C; do not freeze or shake | All adult Fabry doses; verify carton NDC with Chiesi Total Care at billing time as packaging may differ across distribution channels. |
Use the carton NDC on the claim. Confirm 11-digit padded format with your MAC and
with your wholesaler invoice. Chiesi Global Rare Diseases handles US distribution; verify the
labeler code on the actual carton received before submitting J2508 lines — vial vs carton NDC
mismatch is a common rejection at first billing.
No carton-of-multiple-vials SKU. Each carton contains 1 × 20 mg / 10 mL vial.
For an 80 mg dose, draw 4 vials from 4 cartons; for a 100 mg dose, draw 5 vials. Document each
vial's lot and NDC on the infusion record.
Phase 2
Code the claim
Therapeutic IV codes (96365 + 96366), JW for weight-based waste, J2508 only for pegunigalsidase alfa-iwxj.
Administration codes CPT verified May 2026
Elfabrio is enzyme replacement therapy — non-chemo therapeutic IV codes apply.
| Code | Description | When to use |
|---|---|---|
96365 |
Intravenous infusion, for therapy, prophylaxis, or diagnosis (specify substance or drug); initial, up to 1 hour | Primary code for the first hour of Elfabrio. |
96366 |
Each additional hour (List separately in addition to code for primary procedure) | Add for each additional hour beyond the first, up to 8 hours total. Initial infusion runs ~3–4 hours → 96365 + 96366 × 2–3. Maintenance ~2–3 hours → 96365 + 96366 × 1–2. |
96367 |
Additional sequential infusion of a new drug/substance, up to 1 hour | Use for separately identifiable premedication or supportive infusions if given sequentially. |
96374 |
Therapeutic, prophylactic, or diagnostic injection; intravenous push, single or initial | For IV-push premedications (e.g., diphenhydramine 50 mg, methylprednisolone 40 mg). |
96413 |
Chemotherapy IV infusion, up to 1 hour | NOT appropriate. Pegunigalsidase alfa is non-chemo enzyme replacement therapy. Bill 96365. |
Why therapeutic IV (not chemo IV): Pegunigalsidase alfa-iwxj is a recombinant
PEGylated enzyme replacement therapy, not a chemotherapeutic agent or complex monoclonal antibody.
CPT therapeutic infusion codes (96365 / 96366) are correct. Some payers will deny 96413 outright
for J2508 and the appeal will only delay reimbursement.
Modifiers CMS verified May 2026
JW — routine on Elfabrio claims
Elfabrio ships in fixed 20 mg vials and dosing is weight-based, so partial-vial waste is common. JW reports the discarded portion of a single-dose vial. Bill JW with the actual discarded units on a separate claim line — admin line for the units administered, waste line for the discarded units (with JW). Wasted drug is reimbursable but must be reported.
JZ — only when zero waste
Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. For Elfabrio this occurs when the patient's dose is an exact multiple of 20 mg (e.g., 60, 80, 100, 120 kg). One of JZ or JW must be on every J2508 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. Routine pre-infusion clinical assessment is bundled.
340B modifiers (JG, TB)
For 340B-acquired Elfabrio, follow your MAC's current 340B modifier policy. Chiesi's billing materials do not provide 340B-specific instructions for J2508; check Chiesi Total Care for the latest published guidance.
Common error: Forgetting to bill the discarded portion. CMS audits often catch this
— bill the JW line with the actual discarded units alongside the admin line for the units
administered. The total of both lines must reconcile to the total mg drawn from the vials documented
in the chart.
ICD-10-CM by organ system FY2026 verified May 2026
Primary diagnosis is always Fabry disease. Add organ-specific codes for documented end-organ involvement.
| Code | Diagnosis | When to use |
|---|---|---|
E75.21 | Fabry (-Anderson) disease | Primary diagnosis on every J2508 claim. Required by every payer. |
I43 | Cardiomyopathy in diseases classified elsewhere | Add when echo/MRI documents Fabry cardiomyopathy (LVH, fibrosis) |
N18.1–N18.6 | Chronic kidney disease, stage 1–5 | Stage-specific; add for documented Fabry nephropathy |
N18.9 | Chronic kidney disease, unspecified | Use only if stage not documented |
G93.89 | Other specified disorders of brain | Cerebrovascular involvement (TIA/stroke history) |
I63.x | Cerebral infarction | Add for documented Fabry-related stroke |
G60.8 | Other specified hereditary and idiopathic neuropathies | Small-fiber neuropathy / acroparesthesias |
K59.1 | Functional diarrhea / GI manifestations | Optional; common Fabry GI involvement |
L98.8 | Other specified disorders of skin and subcutaneous tissue | Angiokeratomas (corporis diffusum) |
H35.89 | Other specified retinal disorders | Cornea verticillata, retinal vessel tortuosity |
Diagnostic confirmation required for PA approval. Payers expect documentation of
(1) reduced or absent α-galactosidase A enzyme activity (males) AND/OR (2) GLA gene mutation
analysis. Genotype confirmation is required even when enzyme assay is positive because some heterozygous
females have normal-range enzyme activity. Specialist Rx (medical geneticist, cardiologist, or
nephrologist) is also commonly required.
Site of care & place of service Verified May 2026
Major commercial payers run site-of-care UM for high-cost ERTs. Most steer toward office (POS 11) and ambulatory infusion suites (POS 49) over hospital outpatient (POS 22) once tolerability is established. Home infusion is permitted in some plans after the first 6–12 months but requires documented tolerability and a REMS-grade infusion vendor capable of managing anaphylaxis.
| Setting | POS | Claim form | Payer steering |
|---|---|---|---|
| Specialist office (geneticist / cardiologist / nephrologist) | 11 | CMS-1500 / 837P | Preferred by commercial UM |
| Ambulatory infusion suite (AIC) | 49 | CMS-1500 / 837P | Preferred by commercial UM |
| Hospital outpatient (on-campus) | 22 | UB-04 / 837I | Acceptable early; disfavored long-term |
| Hospital outpatient (off-campus PBD) | 19 | UB-04 / 837I | Acceptable early; disfavored long-term |
| Patient home | 12 | CMS-1500 (with home infusion) | Possible after tolerability documented; limited by anaphylaxis risk + 3-day post-infusion observation window |
Home infusion considerations: Hypersensitivity reactions can occur up to 3 days
post-infusion per the FDA label. Most home-infusion programs require documented in-clinic
tolerability for at least 6–12 months and a vendor capable of managing anaphylaxis at the
bedside before transitioning. Verify the patient's plan home-infusion benefit and the vendor's
Fabry-specific protocol before submitting POS 12 claims.
Claim form field mapping Chiesi Total Care + verified May 2026
Standard CMS-1500 / 837P fields for buy-and-bill J2508 claims.
| Information | CMS-1500 box | Notes |
|---|---|---|
| NPI | 17b | Rendering provider |
| NDC qualifier + 11-digit NDC + UoM + qty | 24A shaded area | N4 + carton NDC + ML + total volume drawn (e.g., 40 mL for 4 vials = 80 mg) |
| HCPCS J2508 + JZ (or admin line + JW waste line) | 24D (drug line[s]) | Two lines when waste exists: admin line for mg administered, waste line for mg discarded with JW |
| Drug units | 24G | Actual mg administered + actual mg discarded (JW) summed = total mg drawn |
| CPT 96365 (admin line) | 24D (admin line) | Initial hour |
| CPT 96366 (additional hours) | 24D (admin line) | 2–3 additional hours typical (3–4 hr initial; 1–2 hr maintenance) |
| ICD-10 | 21 | E75.21 primary · organ-specific (I43, N18.x, G93.89, etc.) as supporting Dx |
| PA number | 23 | Required by all major commercial payers; specialist Rx + enzyme/genetic confirmation in chart |
Phase 3
Get paid
Diagnostic confirmation + specialist Rx + payer-specific Fabry policy. Many payers run combined Fabry policies covering Elfabrio, Fabrazyme, and Galafold together.
Payer policy snapshot Reviewed May 2026
Most major payers run combined Fabry policies. Preference between Elfabrio and Fabrazyme is typically driven by contracted price.
| Payer | PA? | Key criteria | Preference |
|---|---|---|---|
| UnitedHealthcare Lysosomal Storage Disease ERT policy |
Yes | Confirmed Fabry Dx (enzyme assay + GLA mutation analysis); specialist consult (medical geneticist, cardiologist, or nephrologist); lifelong commitment | Combined ERT preference; payer may favor whichever ERT is currently contracted |
| Aetna CPB + Medical Drug policies |
Yes | Same as UHC; site-of-care UM steers ICIs/ERTs out of HOPD long-term | Both Elfabrio and Fabrazyme covered; verify current preference at PA submission |
| BCBS plans Vary by plan |
Yes | FDA label-aligned; specialist oversight required | Plan-specific; many run combined Fabry ERT policies |
| Medicare (LCDs) No NCD; MAC LCDs |
No formal PA | FDA-approved Fabry indication; medical necessity documented; specialist Rx | Both ERTs covered; no MAC steering documented |
Step therapy
Some payers may require prior trial of (or contraindication to) the contracted preferred Fabry ERT before approving the non-preferred. Documented Fabrazyme intolerance, anaphylaxis, or high anti-drug antibody titers is generally sufficient justification to switch to Elfabrio — this is the cleanest pathway when Fabrazyme is the preferred. For treatment-naïve starts, verify which ERT is currently preferred by the patient's plan before submitting PA.
Galafold is a separate pathway. If the patient has an "amenable" GLA missense
mutation per the FDA-validated Amicus assay, some payers require trial of Galafold (oral, pharmacy
benefit) before approving any IV ERT. Verify amenability status before submitting Elfabrio PA —
amenable mutations cover ~30–50% of patients depending on population.
Medicare reimbursement CMS Q2 2026 (live)
Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.
Q2 2026 payment snapshot — J2508
Effective April 1 – June 30, 2026 · Based on 4Q25 ASP submissions
ASP + 6%
$223.400
per mg / per unit
70 mg dose (70 kg adult)
$15,638.00
70 units × ASP+6%
80 mg dose (80 kg adult, no waste)
$17,872.00
80 units × ASP+6%
Annualized cost: 70 mg dose × 26 doses (q2wk) = ~$406,588/year
in administered drug. With JW waste line for the 4-vial draw (80 mg total), reimbursed total is
~$464,672/year (26 × 80 × ASP+6%). After ~2% sequestration: ~$455,400/year actual paid
on the full draw.
Coverage
No NCD specific to pegunigalsidase alfa-iwxj. Coverage falls under MAC LCDs for biologics + the generic Fabry/lysosomal storage ERT framework. All MACs cover J2508 for the FDA-approved adult Fabry indication with appropriate ICD-10 (E75.21) and diagnostic confirmation.
Code history
- J2508 — permanent code, "Pegunigalsidase alfa-iwxj" (1 mg). Effective after FDA approval (May 2023). Pre-permanent-code period used unclassified
J3590(unclassified biologics).
Patient assistance — Chiesi Total Care Chiesi verified May 2026
- Chiesi Total Care / Elfabrio Patient Support: 1-833-444-FABRY (1-833-444-3227) — benefits investigation, prior authorization assistance, appeal support, dedicated rare-disease nurse case management
- Commercial copay assistance (excludes Medicare, Medicaid, federal program patients per AKS guidance)
- PAP: free product for uninsured / underinsured patients meeting income requirements
- Foundations (Medicare): refer to PAN, HealthWell, NORD, National Fabry Disease Foundation — verify open Fabry / lysosomal storage funds quarterly
- Patient advocacy: fabrydisease.org (National Fabry Disease Foundation), fabryinternational.org
Need to model what a specific Fabry patient will actually pay after copay assistance, deductible,
coinsurance, and OOP max? Run a CareCost Estimate — J2508
pre-loaded.
Phase 4
Fix problems
JW omission, off-label pediatric, and missing diagnostic confirmation are the top three.
Common denials & how to fix them
| Denial reason | Common cause | Fix |
|---|---|---|
| JW missing on adult claim | Wasted drug not reported on weight-based dose | Add JW line for discarded units. Admin line for the units administered; JW line for the wasted units. One of JZ or JW must be on every J2508 claim. |
| JZ used when waste actually occurred | Patient's weight not an exact multiple of 20 mg but JZ submitted | Resubmit with admin line + JW waste line. Use the per-weight vial-math table to pre-calculate. |
| Total billed mg exceeds vial draw | Admin units + JW units > total vials drawn × 20 mg | Reconcile chart documentation to claim. Total billed mg must match total mg drawn from vials (vials × 20 mg). |
| Off-label pediatric use | Patient <18 years old; Elfabrio not approved for pediatric Fabry as of May 2026 | Switch to Fabrazyme (J0180, ≥2 yr label) or, if amenable mutation, Galafold. Re-check Elfabrio pediatric status at PA submission. |
| Missing diagnostic confirmation | PA submitted without enzyme assay or GLA mutation analysis | Submit lab results in PA packet. Both confirmatory tests are typically required because heterozygous females may have normal-range enzyme activity. |
| Wrong admin code (96413) | Chemo IV billed instead of therapeutic IV | Resubmit with 96365 + 96366. Pegunigalsidase alfa is non-chemo enzyme replacement therapy. |
| Step therapy — preferred Fabry ERT not tried | Plan requires trial of contracted preferred ERT (Fabrazyme or Galafold for amenable mutations) first | Document prior Fabrazyme intolerance, anaphylaxis, high anti-drug antibody titers, or amenability negative. Or switch to the preferred ERT. |
| Wrong NDC format | Vial-level NDC submitted instead of carton NDC, or 10-digit not padded to 11 | Use the carton NDC in 11-digit padded format. Verify with Chiesi Total Care and your wholesaler invoice. |
| Site of care (HOPD long-term) | HOPD administration after first 6–12 months on commercial plan with site-of-care UM | Move to specialist office (POS 11) or AIC (POS 49). Submit medical necessity letter if HOPD required (e.g., severe IAR history). |
Frequently asked questions
What is the HCPCS code for Elfabrio?
Elfabrio (pegunigalsidase alfa-iwxj) is billed under HCPCS J2508 —
"Pegunigalsidase alfa-iwxj." Each milligram equals one billable unit. Standard adult dose is
1 mg/kg IV every 2 weeks, so a 70 kg patient is billed as 70 units of J2508 per infusion.
Elfabrio was FDA-approved May 2023 (BLA 761161) and is the first PEGylated α-galactosidase A
ERT — a direct alternative to Fabrazyme (J0180 agalsidase beta).
How many units do I bill for an Elfabrio dose?
Bill the actual mg administered as units (1 mg = 1 unit) plus a separate JW line for
any wasted mg from the 20 mg single-dose vial. A 70 kg adult receives 70 mg = 70 units (4 vials
drawn = 80 mg, 10 mg waste billed JW). A 50 kg patient receives 50 mg = 50 units (3 vials drawn
= 60 mg, 10 mg waste). One of JZ (zero waste) or JW (waste reported) must be on every J2508 claim
per CMS's July 2023 single-dose container policy.
What administration CPT do I use for Elfabrio?
CPT 96365 for the initial hour of therapeutic IV infusion (non-chemo) plus
96366 for each additional hour. The first Elfabrio infusion runs 3–4 hours per
Chiesi protocol, so expect 96365 + 96366 × 2–3. Subsequent infusions in tolerant
patients may shorten to 1.5–3 hours (96365 + 96366 × 1–2). Do NOT bill 96413 —
pegunigalsidase alfa is enzyme replacement therapy, not chemo.
Do I bill JZ or JW for Elfabrio?
Bill JW on most Elfabrio claims. Vials are fixed at 20 mg and dosing is weight-based
(1 mg/kg), so partial-vial waste is the rule. Patients whose dose is an exact multiple of 20 mg
(e.g., 60 kg = 60 mg, 80 kg = 80 mg, 100 kg = 100 mg) produce zero waste — bill JZ.
All other weights produce waste — bill JW with the discarded units on a separate claim line.
What is the Medicare reimbursement for J2508?
For Q2 2026, the Medicare Part B payment limit for J2508 is $223.400 per mg (ASP + 6%). A 70 mg dose reimburses at approximately $15,638.00 per infusion; an 80 mg dose at approximately $17,872.00. Annualized cost (Medicare ASP+6%, 70 kg adult, 26 doses): approximately $406,588/year on administered drug, or ~$464,672/year on total mg drawn (admin + JW waste reimbursed together).
How does Elfabrio compare to Fabrazyme?
Same dosing (1 mg/kg IV every 2 weeks) and same indication (adult Fabry disease). Three meaningful differences: (1) PEGylation — Elfabrio is conjugated with PEG to extend half-life and reduce immunogenicity vs Fabrazyme's recombinant agalsidase beta; (2) Pediatric — Fabrazyme is FDA-approved for ages ≥2 years (2018 expansion); Elfabrio is currently adult-only; (3) Vial format — Fabrazyme ships in 5 mg and 35 mg lyophilized vials, Elfabrio ships in 20 mg/10 mL liquid vials (no reconstitution). Q2 2026 Medicare ASP+6% per mg is approximately $223.40 for Elfabrio vs ~$227.58 for Fabrazyme — pricing essentially at parity. See full side-by-side.
Does Elfabrio require premedication?
Premedication is recommended (not formally required by FDA label) to mitigate infusion-associated reactions and hypersensitivity. Standard protocol: acetaminophen 650–1000 mg PO + diphenhydramine 25–50 mg PO/IV + corticosteroid (e.g., methylprednisolone 20–100 mg IV) 30–60 minutes before each infusion. Bill IV premedications separately under their own J-codes plus 96374 for IV push. Hypersensitivity reactions including anaphylaxis can occur during infusion and up to 3 days post-infusion.
Does Elfabrio have a boxed warning?
No boxed warning. Warnings and Precautions in the FDA label include: (1) hypersensitivity reactions including anaphylaxis (during infusion and up to 3 days post-infusion); (2) infusion-associated reactions (premedication recommended); (3) Membranoproliferative Glomerulonephritis (MPGN) — rare but reported; (4) embryo-fetal toxicity. Fabrazyme also has no boxed warning. By comparison, Aldurazyme (the original lysosomal storage ERT for MPS I) does carry a boxed warning for anaphylaxis.
Reference
Sources & methodology
Every claim on this page is sourced. Methodology and review history below.
Source documents
- Elfabrio official site (Chiesi Global Rare Diseases)
- DailyMed — ELFABRIO (pegunigalsidase alfa-iwxj) Prescribing Information
- FDA Drugs@FDA — Elfabrio approval letter and label
- CMS — Medicare Part B Drug ASP Pricing File
- SEER CanMED — HCPCS J2508 reference
- UnitedHealthcare — Lysosomal Storage Disease ERT Coverage Policy
- Aetna — Clinical Policy Bulletins (Fabry / lysosomal storage)
- FDA National Drug Code Directory
- National Fabry Disease Foundation — patient and clinician resources
- Protalix BioTherapeutics — pegunigalsidase alfa development background
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) | Semi-annual | Manual review against published payer policy documents. |
| HCPCS / CPT / modifier rules | Annual | Reviewed against CMS HCPCS quarterly files and AMA CPT releases. |
| NDC, dosing, FDA label, indication | Event-driven | Tied to manufacturer document version + FDA label revision date. Pediatric labeling expansion is the most likely future change. |
Reviewer
Pending SME review. This page is staff-authored from primary sources (FDA, CMS,
Chiesi/Protalix, 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 — particularly the Elfabrio NDC and current
Chiesi Total Care PAP terms.
Change log
- — Initial publication. ASP data: Q2 2026. Manufacturer source: Chiesi 2025. FDA label: May 2023 approval (BLA 761161). Adult-only Fabry indication. Companion to Fabrazyme (J0180) reference page.
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, and warnings are verified against the current FDA label revision. We do not paraphrase from billing-software vendor blogs.