HCPCS
J1569
1 unit = 500 mg
Phase 1
Identify what you're billing
The 500 mg unit basis is the single most error-prone field on IVIG claims. Confirm it first.
500 mg unit basis — the biller error trap CMS HCPCS Q2 2026
All current US IVIG J-codes use a 500 mg unit. Forget this and your claim is wrong by a factor of 500.
Most specialty drug J-codes use a 1 mg unit (e.g., J9299 Opdivo, J9271 Keytruda, J0202 Lemtrada). IVIG codes do not. CMS standardized on a 500 mg unit for the entire IVIG family (J1459, J1554, J1557, J1561, J1566, J1568, J1569, J1572, J1599) because typical IVIG doses run 20–100 g per infusion — billing per mg would push unit counts into 5- and 6-digit territory and break claim-form unit-edit logic.
The conversion is always: total mg administered ÷ 500 = units billed.
A 35 g (35,000 mg) dose = 70 units. A 25 g dose = 50 units. A 50 g loading dose = 100 units.
Never bill the mg figure directly.
| Dose (g) | Dose (mg) | Units billed (J1569) | Vials used |
|---|---|---|---|
| 10 g | 10,000 mg | 20 units | 1 × 10 g vial |
| 20 g | 20,000 mg | 40 units | 1 × 20 g vial |
| 25 g | 25,000 mg | 50 units | 1 × 20 g + 1 × 5 g |
| 30 g | 30,000 mg | 60 units | 1 × 30 g vial |
| 35 g (typical PI 70 kg @ 500 mg/kg) | 35,000 mg | 70 units | 1 × 30 g + 1 × 5 g |
| 50 g | 50,000 mg | 100 units | 1 × 30 g + 1 × 20 g |
| 100 g (large MMN load fraction) | 100,000 mg | 200 units | 3 × 30 g + 1 × 10 g |
Cross-check on every claim. Pull the dispense record (mg administered), divide by 500, and
confirm the unit field on the 837 / CMS-1500 matches. Most IVIG denials and overpayment recoupments stem
from the unit field, not the dose itself.
Gammagard Liquid (J1569) vs Gammagard S/D (J1566) CMS HCPCS verified May 2026
Two distinct Takeda/Baxter products with separate HCPCS codes. The Liquid product is the standard of care today; S/D is largely legacy.
| Gammagard Liquid | Gammagard S/D | |
|---|---|---|
| HCPCS | J1569 | J1566 |
| Form | 10% liquid (100 mg/mL), ready-to-use | Lyophilized powder, requires reconstitution |
| Stabilizer | Glycine | Glycine + glucose (older) |
| IgA content | ~37 mcg/mL (low) | <1 mcg/mL (very low — preferred for IgA-sensitive patients historically) |
| Unit basis | 500 mg = 1 unit | 500 mg = 1 unit |
| Vial sizes | 1, 2.5, 5, 10, 20, 30 g | 2.5, 5, 10 g lyophilized + diluent |
| Indications | PI (≥2 yr), MMN | PI, ITP, B-cell CLL, pediatric HIV, Kawasaki disease (legacy label) |
| Manufacturer | Takeda (originated Baxter/Baxalta) | Takeda (originated Baxter/Baxalta) |
| Current US use | Standard of care — most US IVIG claims | Legacy — minimal current volume |
Confirm before billing. Pull the actual NDC from the dispense / inventory record. If
the product administered is reconstituted from a lyophilized powder + diluent, it is Gammagard S/D
(
J1566), not Gammagard Liquid (J1569). The two codes have different ASPs and
different payer policies.
Dosing by indication FDA label verified Apr 2026
From the FDA prescribing information and AAAAI / AAN guidelines.
| Indication | Dose | Frequency | Target / endpoint | Typical 70 kg dose |
|---|---|---|---|---|
| Primary humoral immunodeficiency (PI) XLA, CVID, SCID, WAS, IgG subclass deficiency |
300–600 mg/kg | Every 3–4 weeks | IgG trough ≥500–1,000 mg/dL; clinical reduction in serious bacterial infections | 21–42 g (typical 35 g) |
| Multifocal motor neuropathy (MMN) Adults, EMG-confirmed conduction block |
Loading 2.0 g/kg over 2–5 days; maintenance 0.5–2.4 g/kg/month | Loading once; maintenance monthly (often split 0.5–1.0 g/kg q2–4w) | Stabilization or improvement of muscle strength; titrate to lowest effective dose | Load 140 g; maintenance 35–168 g/month |
| CIDP (off-label) Privigen, Gamunex-C, Panzyga have on-label CIDP — Gammagard Liquid does not |
Loading 2.0 g/kg over 2–5 days; maintenance 1.0 g/kg q3w | Maintenance every 3 weeks | INCAT / MRC sum score improvement | Load 140 g; maintenance 70 g q3w |
| Secondary immunodeficiency (off-label) CLL, post-HSCT, hypogammaglobulinemia from rituximab/anti-CD20 |
300–500 mg/kg | Every 3–4 weeks | IgG trough ≥500 mg/dL + reduction in serious infections (payer requires both) | 21–35 g |
| ITP (off-label) Privigen has on-label ITP; Gammagard Liquid does not |
1.0 g/kg/day × 1–2 days OR 0.4 g/kg/day × 5 days | Single course (re-treat as needed) | Platelet rise to clinically safe range (typically >30–50K) | 70 g/day × 1–2 days |
Off-label IG use is common but not automatic. Most major payers will cover off-label
IVIG for CIDP, secondary immunodeficiency, and ITP under medical-necessity criteria, but require
documentation of dx, prior therapy failures, and (for SID) demonstrated infection burden + IgG <500.
Off-label uses are billed under the same J1569 code with the appropriate ICD-10.
Worked example — first-year billing for a 70 kg PI patient on monthly Gammagard Liquid
# PI maintenance: 500 mg/kg q4w
Dose per infusion: 70 kg × 500 mg/kg = 35,000 mg (35 g)
Units billed per dose: 35,000 ÷ 500 = 70 units (J1569)
Modifier: JZ (single-dose vials, no waste — using 1 × 30 g + 1 × 5 g)
Admin: 96365 (initial hour) + 96366 × 3 (3 additional hours, 4-hour total infusion)
# Year-1 totals
Total infusions/year: 12 (q4w schedule)
Total drug units: 840 units (12 × 70)
Drug ASP+6% per dose (Q2 2026): 70 × $49.081 = ~$3,435.67
Annual drug ASP+6%: ~$41,228 before sequestration
Dose per infusion: 70 kg × 500 mg/kg = 35,000 mg (35 g)
Units billed per dose: 35,000 ÷ 500 = 70 units (J1569)
Modifier: JZ (single-dose vials, no waste — using 1 × 30 g + 1 × 5 g)
Admin: 96365 (initial hour) + 96366 × 3 (3 additional hours, 4-hour total infusion)
# Year-1 totals
Total infusions/year: 12 (q4w schedule)
Total drug units: 840 units (12 × 70)
Drug ASP+6% per dose (Q2 2026): 70 × $49.081 = ~$3,435.67
Annual drug ASP+6%: ~$41,228 before sequestration
Infusion rate titration FDA label verified Apr 2026
Slow start, titrate up. Total per-dose infusion runs 2–6 hours. Drives 96366 unit count.
| Step | Rate (mg/kg/min) | Rate (mL/kg/hr at 10%) | Duration before next titration | Notes |
|---|---|---|---|---|
| Initial | 0.5 mg/kg/min | 0.3 mL/kg/hr | 30 min | For all naive patients |
| Step 2 | 1.0 mg/kg/min | 0.6 mL/kg/hr | 30 min | If tolerated |
| Step 3 | 2.0 mg/kg/min | 1.2 mL/kg/hr | 30 min | If tolerated |
| Step 4 | 4.0 mg/kg/min | 2.4 mL/kg/hr | 30 min | If tolerated |
| Maintenance (max) | 8.0 mg/kg/min | 4.8 mL/kg/hr | Continue to end | Maximum FDA-labeled rate; reduce in patients at risk for renal/thrombotic AEs |
Why this drives admin coding. A 35 g dose at the maximum 8 mg/kg/min rate (after full
titration) takes ~75 minutes; with the mandatory titration schedule (4 × 30 min steps + ~45 min at
max) the realistic infusion is 3–4 hours. For a stable maintenance patient bumped
to higher starting rate, expect 2–3 hours. Bill
96365 for initial hour + 96366
for each additional hour.
Slow rates for renal / thrombotic risk. Per the boxed warning, patients ≥65 yr or
with diabetes, prior renal disease, dehydration, sepsis, or paraproteinemia should be initiated and
maintained at the minimum effective rate — typically not exceeding 3.3 mg/kg/min
even at maintenance. This extends infusion time and increases 96366 units billed.
NDC reference (Gammagard Liquid vials) Takeda label verified May 2026
| Vial size (mg / mL) | Concentration | NDC family | Use |
|---|---|---|---|
| 1 g / 10 mL | 10% (100 mg/mL) | 0944-2700-xx (Takeda IG family) | Pediatric / small adult; partial dose top-off |
| 2.5 g / 25 mL | 10% | 0944-2700-xx | Pediatric / small adult; combo with larger vials |
| 5 g / 50 mL | 10% | 0944-2700-xx | Top-off vial for 25, 35, 45 g doses |
| 10 g / 100 mL | 10% | 0944-2700-xx | Common adult vial |
| 20 g / 200 mL | 10% | 0944-2700-xx | Common adult vial |
| 30 g / 300 mL | 10% | 0944-2700-xx | Largest vial; primary base for 30–35 g PI maintenance doses |
Confirm exact 11-digit NDC at billing time. Takeda has issued multiple package
configurations and lot families across the IG portfolio. Pull the NDC from the actual carton/vial
you administered — do not copy from a prior claim. NDC submission qualifier is
N4
in the CMS-1500 24A shaded area, with unit-of-measure ML and total mL administered.
Vial selection minimizes waste. Match dose to available vial sizes to keep the JZ
modifier eligible. Example: a 35 g dose pairs cleanly as 1 × 30 g + 1 × 5 g (zero waste,
bill JZ). A 33 g dose forced into 1 × 30 g + 1 × 5 g leaves 2 g (4 units) waste — bill
JW for 4 units on a separate line.
Phase 2
Code the claim
Therapeutic IV (96365 + 96366), NOT chemo. JZ or JW on every line. Indication-specific ICD-10.
Administration codes CPT verified May 2026
IVIG is a non-chemo therapeutic infusion. Use 96365 for the first hour and 96366 for each additional hour.
| Code | Description | When to use |
|---|---|---|
96365 |
Intravenous infusion, for therapy/prophylaxis/diagnosis; initial, up to 1 hour | Primary code for Gammagard Liquid IV. One unit per infusion encounter. |
96366 |
Intravenous infusion; each additional hour (list separately in addition to 96365) | Add one unit for each additional hour beyond the first. A 4-hour infusion bills 96365 × 1 + 96366 × 3. |
96367 |
Sequential infusion, additional substance/drug | If a separate substance is infused sequentially (e.g., separate premedication infusion). |
96413 / 96415 |
Chemotherapy administration, IV infusion | NOT appropriate. IVIG is not chemotherapy. Use of 96413 will trigger denial or recoupment. |
96372 |
Therapeutic, prophylactic, or diagnostic injection (subcutaneous or IM) | For SC immune globulin push administration only when applicable; routine SCIG home administration uses S9338 / S9354 / S9355 (HCPCS) under home infusion benefit. |
Hour math: count from infusion start to stop. A 2.5-hour infusion bills 96365 × 1 +
96366 × 1 (the second 96366 hour requires ≥31 minutes of the additional hour). Document
start/stop times in the chart for audit.
Modifiers CMS verified May 2026
JZ — required when no waste
Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. Gammagard Liquid vials (1, 2.5, 5, 10, 20, 30 g) are all single-dose. When the prescriber sizes the dose to match available vials (e.g., 35 g = 30 g + 5 g vials, fully administered), bill JZ on the J1569 line.
JW — required when waste occurs
JW reports the discarded portion of a single-dose vial. Common scenarios:
- Weight-based pediatric PI dose that doesn't match vial sizes (e.g., 12 kg child at 500 mg/kg = 6 g; uses 1 × 10 g vial, discards 4 g → JW for 8 units)
- Weight-based MMN dose that requires partial-vial administration
- Provider-driven dose adjustment that no longer matches the dispensed vial size
Bill JW on a separate claim line with the units of waste. One of JZ or JW must be on every J1569 claim per the July 2023 CMS policy.
JW math — remember the 500 mg unit. If you waste 4 g (4,000 mg), the JW units are
4,000 ÷ 500 = 8 units. Same conversion as the administered units. Don't mix
unit bases on the same 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., monthly PI follow-up coupled with infusion). Routine pre-infusion clinical assessment is bundled.
340B modifiers (JG, TB)
For 340B-acquired Gammagard Liquid, follow your MAC's current 340B modifier policy. Hospital outpatient IVIG is a frequent 340B-eligible drug; verify institutional 340B contract pharmacy logic for billing.
ICD-10-CM by indication FY2026 verified May 2026
PI and MMN are FDA-on-label. CIDP, secondary immunodeficiency, and ITP are commonly billed off-label with payer-specific medical necessity.
| Indication | ICD-10 | Notes |
|---|---|---|
| Primary immunodeficiency (on-label) | ||
| X-linked agammaglobulinemia (XLA) | D80.0 | Bruton's; typical PI initiation in pediatrics |
| Common variable immunodeficiency (CVID) | D83.x | D83.0 / D83.1 / D83.2 / D83.8 / D83.9 by sub-type |
| Other hypogammaglobulinemia | D80.x | D80.1 (non-familial), D80.3 (selective IgG subclass), D80.6, D80.8, D80.9 |
| Combined immunodeficiencies (incl. SCID) | D81.x | D81.0–D81.9 by sub-type; SCID = D81.1, D81.2, D81.4 |
| Wiskott-Aldrich syndrome | D82.0 | WAS |
| Other PI with predominantly antibody defects | D82.x / D83.x | Use most specific code in patient record |
| Multifocal motor neuropathy (on-label) | ||
| Multifocal motor neuropathy | G61.82 | EMG/NCS conduction block evidence in chart |
| Off-label (payer medical necessity) | ||
| CIDP | G61.81 | Privigen, Gamunex-C, Panzyga have on-label CIDP — payers may steer there |
| Secondary immunodeficiency post-HSCT / CLL / rituximab | D83.x / D84.x + underlying dx | Most payers require IgG <500 mg/dL + documented infection burden |
| Immune thrombocytopenia (ITP) | D69.3 | Privigen has on-label ITP — payers may steer there |
| Guillain-Barré syndrome | G61.0 | Acute treatment, off-label for Gammagard Liquid (Gamunex-C is on-label for GBS) |
| Myasthenia gravis (acute exacerbation) | G70.0x | Off-label rescue; payer-specific |
Document IgG trough and infection history for PI. Most payers require baseline IgG
level + functional antibody response (e.g., post-vaccine titers) for initial PI authorization, plus
IgG troughs every 3–6 months for continued authorization. For MMN, expect EMG/NCS evidence of
conduction block in the prior auth packet.
Site of care & place of service UHC / Aetna verified May 2026
IVIG site-of-care steerage is among the most aggressive of any specialty drug class — payers actively redirect to home infusion or ambulatory infusion centers.
UnitedHealthcare, Aetna, Cigna, Humana, and most major BCBS plans run a standalone IVIG site-of-care UM program. Hospital outpatient infusion (POS 19/22) is broadly disfavored. The preferred pathway is home infusion (POS 12) via a contracted specialty infusion provider, with ambulatory infusion suite (POS 49) and physician office (POS 11) as next-best options.
| Setting | POS | Claim form | Payer steering |
|---|---|---|---|
| Patient home (specialty infusion vendor) | 12 | CMS-1500 / 837P (with home infusion S-codes) | Most preferred by commercial UM — lowest unit cost |
| Ambulatory infusion suite (AIC) | 49 | CMS-1500 / 837P | Preferred alternative when home not feasible |
| Physician office | 11 | CMS-1500 / 837P | Acceptable; lower cost than HOPD |
| Hospital outpatient (on-campus) | 22 | UB-04 / 837I | Disfavored — commonly requires HOPD-specific medical necessity (port complications, recent acute illness, vascular access issues) |
| Hospital outpatient (off-campus PBD) | 19 | UB-04 / 837I | Disfavored same as on-campus |
| Inpatient (acute) | 21 | UB-04 / 837I | Acceptable when IVIG is part of acute admission (severe MMN, IgG <100, sepsis with secondary IGD) |
Home infusion billing: when administered at POS 12 by a contracted specialty home
infusion provider, additional HCPCS codes apply:
S9338 (home infusion therapy, IVIG; per
diem) for commercial payers, plus the J1569 drug units. Medicare's home IVIG demonstration (now
permanent for PI) covers home administration via Part B with limited per-visit reimbursement.
Site-of-care denial pattern: when a stable PI patient on Gammagard Liquid is
administered in HOPD, expect retrospective UM review and potential downcode to home-infusion-equivalent
rates. Document HOPD-specific medical necessity (vascular access failure, severe prior reaction
requiring monitored setting, etc.) at PA renewal.
Claim form field mapping CMS-1500 / 837P verified May 2026
Standard buy-and-bill mapping for office, AIC, and home infusion claims.
| Information | CMS-1500 box | Notes |
|---|---|---|
| NPI | 17b / 33a | Rendering / billing provider NPIs |
| NDC qualifier + 11-digit NDC + UoM + qty | 24A shaded area | N4 + actual vial NDC + ML + total mL administered (e.g., 350 mL for 35 g) |
| HCPCS J1569 + JZ (or JW for waste) | 24D (drug line) | Mark JZ when no waste; JW on separate line for discarded units |
| Drug units | 24G | Total mg ÷ 500 — e.g., 70 for a 35 g dose |
| CPT 96365 (admin line) | 24D (admin line) | Initial hour, 1 unit |
| CPT 96366 (additional hours) | 24D (admin line) | 1 unit per additional hour beyond the first |
| ICD-10 | 21 | Indication-specific (D80.x, D81.x, D82.x for PI; G61.82 for MMN) |
| PA number | 23 | Required by all major payers |
| Home infusion S-code (if applicable) | 24D | S9338 per diem for commercial home infusion |
Phase 3
Get paid
PA, biomarker docs (IgG / EMG), site-of-care logic, and brand interchangeability all gate payment.
Payer policy snapshot Reviewed May 2026
All major payers require PA, indication-specific clinical docs, and run aggressive site-of-care UM for IVIG.
| Payer | PA? | Required clinical docs | Site-of-care UM | Brand preference |
|---|---|---|---|---|
| UnitedHealthcare Medical Benefit Drug Policy / OptumRx managed |
Yes | PI: dx + IgG <500 baseline + functional antibody response. MMN: EMG conduction block. Off-label: payer-specific medical necessity. | Aggressive — home infusion strongly preferred via Optum-contracted vendors | Rotates among Gammagard Liquid, Privigen, Octagam, Gamunex-C based on contracting; switching mid-therapy requires new PA |
| Aetna CPB 0206 (IVIG) |
Yes | Same as above + documented serious bacterial infections in prior 12 mo for PI continuation | Yes — separate site-of-care policy steers IVIG out of HOPD after first 3 months unless HOPD-specific necessity documented | Product-level preferred list; verify per plan |
| Cigna / Evernorth Coverage Policy 1218 |
Yes | Same; off-label requires NCCN- or specialty-society-supported indication | Yes — Accredo home infusion steerage | Accredo manages product selection |
| BCBS plans Vary by plan; many use Carelon / AIM medical UM |
Yes | Plan-specific; aligns with AAAAI PI guidelines + AAN MMN guidelines | Plan-specific; most have IVIG site-of-care steering | Plan-specific; many have product-specific PA forms |
| Medicare Part B No NCD; MAC LCDs apply |
No PA (but local coverage rules) | PI dx + IgG levels + clinical infection history per MAC LCD | Home IVIG demo permanent for PI; otherwise office / AIC / HOPD per MAC | Pricing parity by ASP; brand selected by provider/contract |
Step therapy
For PI, step therapy through other IVIG products is uncommon — PI is a chronic indication and payers respect product continuity if the patient is stable. For off-label indications (CIDP, SID, ITP), many payers require a step through a product with an on-label indication for that condition before approving Gammagard Liquid (e.g., trial of Privigen for CIDP, Privigen for ITP, or Gamunex-C for GBS).
Brand interchangeability among IVIG / IGSC products Payer policy May 2026
Clinically similar, contractually distinct. Switching products almost always requires a new PA.
IVIG products differ in IgA content, sugar / stabilizer (glycine, proline, sucrose — sucrose largely retired post-renal warning), osmolality, sodium content, and concentration (5%, 10%, 16.5% SCIG). While clinically interchangeable for most patients, payers treat each product as a distinct formulary item with its own preferred status, contracting, and PA requirements.
| Product | HCPCS | Concentration / route | Manufacturer | On-label highlights |
|---|---|---|---|---|
| Gammagard Liquid (this page) | J1569 | 10% IV | Takeda | PI (≥2 yr), MMN |
| Privigen | J1459 | 10% IV | CSL Behring | PI (≥3 yr), CIDP, ITP |
| Octagam 10% | J1568 | 10% IV | Octapharma | PI, ITP |
| Octagam 5% | J1568 | 5% IV | Octapharma | Dermatomyositis |
| Gamunex-C | J1561 | 10% IV / SC | Grifols | PI, ITP, CIDP |
| Gammaplex | J1557 | 5% / 10% IV | Bio Products Lab / Grifols | PI, ITP |
| Bivigam | J1556 | 10% IV | ADMA Biologics | PI |
| Asceniv | J1554 | 10% IV (high titer RSV) | ADMA Biologics | PI; high-titer for select PI patients |
| Panzyga | J1576 | 10% IV | Pfizer / Octapharma | PI, ITP, CIDP |
| Cuvitru (SC) | J1555 | 20% SC | Takeda | PI — SC route, weekly self-administered |
| Hizentra (SC) | J1559 | 20% SC | CSL Behring | PI, CIDP — SC route, weekly |
| Gammagard S/D (lyophilized) | J1566 | 5% / 10% IV (reconstituted) | Takeda | PI, ITP, B-CLL, pediatric HIV, Kawasaki (legacy) |
| HyQvia (facilitated SC) | J1575 | 10% SC + hyaluronidase | Takeda | PI — large-volume SC q3–4w (Takeda's facilitated SC) |
Switching pitfalls:
- New PA almost always required — the new product gets its own PA file
- Re-dose titration usually required (start at slow rate, retitrate over 4 weeks)
- IgA-deficient patients should avoid products with detectable IgA — verify product IgA spec before switch
- SCIG <-> IVIG switches change the J-code and admin coding entirely (96365 IV vs 96372 SC vs S9338 home infusion)
- Patients stable on a specific product may experience tolerability differences after switch (reactions, fatigue, headache)
Sister Takeda IG products (same patient assistance program / OnePath): Cuvitru (SC,
J1555), HyQvia (facilitated SC, J1575), Gammagard S/D (J1566).
These share Takeda's billing infrastructure but each has its own HCPCS, NDC family, and FDA label.
Medicare reimbursement CMS Q2 2026 (live)
Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.
Q2 2026 payment snapshot — J1569
Effective April 1 – June 30, 2026 · Based on 4Q25 ASP submissions
ASP + 6%
$49.081
per 500 mg unit
35 g PI dose (70 units)
$3,435.67
70 × ASP+6%
Per mg equivalent
$0.098
$49.081 ÷ 500
Annualized cost for monthly PI maintenance (12 doses × 35 g):
12 × $3,435.67 = ~$41,228/year in
Medicare drug payment (ASP+6%). MMN maintenance ranges roughly $30K–$200K/year
depending on dose (0.5–2.4 g/kg/month). After ~2% sequestration: actual paid is roughly ASP + 4.3%.
Coverage
No NCD specific to Gammagard Liquid; coverage falls under MAC LCDs for IVIG and the Medicare IVIG home infusion benefit (Part B), now permanent for primary immunodeficiency. All MACs cover J1569 for FDA-approved indications (PI, MMN) with appropriate ICD-10 and clinical documentation.
Code history
- J1569 — permanent code, descriptor "Injection, immune globulin (Gammagard Liquid), non-lyophilized, (e.g. liquid), 500 mg." All current US IVIG J-codes use the 500 mg unit basis.
- Pre-permanent-code period for new IVIG products typically uses unclassified
J3490with NDC documentation.
Patient assistance — Takeda OnePath Takeda verified May 2026
- Takeda Patient Support / OnePath: 1-866-861-1750 — benefits investigation, prior authorization assistance, appeal support, copay assistance, free product for eligible patients
- OnePath Co-Pay Assistance: commercial copay support for eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients per OIG guidance)
- OnePath Patient Assistance Program: free product for uninsured / underinsured patients meeting income requirements
- Foundations (Medicare patients): for Medicare patients who cannot use manufacturer copay programs, refer to PAN Foundation, HealthWell Foundation, Patient Advocate Foundation, and The Assistance Fund — verify open IVIG / immunodeficiency funds quarterly (these funds open and close based on donations)
- OnePath also covers Takeda's other IG products (Cuvitru SC, HyQvia, Gammagard S/D) under the same contact / portal
Need to model what a specific patient will actually pay after OnePath copay assistance, deductible,
coinsurance, and OOP max? Run a CareCost Estimate — J1569 pre-loaded.
Phase 4
Fix problems
Unit-basis errors, wrong admin code, missing JZ/JW, and HOPD site-of-care denials are the top four.
Common denials & how to fix them
| Denial reason | Common cause | Fix |
|---|---|---|
| Unit field grossly out of range | Billed mg directly instead of mg ÷ 500 (e.g., 35,000 units instead of 70) | Resubmit with corrected units. Convert mg ÷ 500 = units. Apply same fix to JW waste line. |
| Wrong admin code (96413) | Chemo IV billed instead of therapeutic IV | Resubmit with 96365 + 96366 × N. IVIG is a non-chemo therapeutic infusion. |
| JZ / JW missing | Single-dose vial claim without modifier | Resubmit with JZ if no waste, or JW on a separate line for discarded units. Required since 7/1/2023. |
| JW waste units in mg | Wasted 4 g billed as 4,000 units instead of 8 | Convert waste mg ÷ 500 = units. Same conversion as administered units. |
| Wrong product code (J1566 instead of J1569) | Gammagard S/D (lyophilized) code submitted for Liquid product (or vice versa) | Verify NDC on dispense record. Liquid = J1569; S/D = J1566. |
| Site of care (HOPD) | HOPD administration without HOPD-specific medical necessity | Move to home infusion (POS 12) or AIC (POS 49). For HOPD continuation, document vascular access issues, prior reaction requiring monitored setting, or acute medical complexity. |
| PA not on file / expired | New patient or PA expiration mid-year | Submit / re-submit PA with PI dx, IgG levels, infection history (PI) or EMG/NCS (MMN). Most payers PA is annual. |
| Brand mismatch (Privigen / Octagam expected) | Payer's preferred IVIG product is not Gammagard Liquid; switched without new PA | Submit new PA for Gammagard Liquid with rationale, or switch to payer's preferred product. |
| Off-label denial (CIDP, ITP, GBS) | ICD-10 indicates off-label indication; payer prefers product with on-label indication for that dx | Submit medical-necessity letter with prior failed therapies and rationale, or switch to on-label product (Privigen for CIDP/ITP, Gamunex-C for GBS). |
| Hours-not-supported denial on 96366 | Excessive 96366 units without start/stop documentation | Resubmit with chart documentation of infusion start, end, and titration steps. Each 96366 unit requires ≥31 minutes of additional infusion time. |
Frequently asked questions
What is the HCPCS code for Gammagard Liquid?
Gammagard Liquid is billed under HCPCS J1569 — "Injection, immune globulin
(Gammagard Liquid), non-lyophilized, (e.g. liquid), 500 mg." One unit equals 500 mg, NOT
1 mg. This is the most common billing error on IVIG claims.
How many units do I bill for a 35 g Gammagard Liquid dose?
Bill 70 units of J1569 for a 35 g (35,000 mg) dose:
35,000 ÷ 500 = 70. For a 25 g dose, bill 50 units. For a 10 g dose, bill 20 units. The
conversion is always: total mg ÷ 500 = units billed.
Is Gammagard Liquid the same as Gammagard S/D?
No. Gammagard Liquid (10% liquid IVIG, ready to use) is HCPCS J1569. Gammagard S/D
(lyophilized solvent/detergent IGIV requiring reconstitution) is HCPCS J1566. Different
products, different ASPs, different payer policies. Confirm the actual NDC on the dispense record
before submitting the claim.
What administration CPT do I use?
CPT 96365 for the initial up-to-1-hour infusion, plus 96366 for each
additional hour. A typical 4-hour Gammagard Liquid infusion bills 96365 × 1 + 96366 × 3.
Do NOT use 96413 (chemo) — IVIG is a non-chemotherapy therapeutic infusion.
Do I bill JZ or JW?
Bill JZ when the dose matches available vial sizes and the entire single-dose vial(s) are
administered (e.g., 35 g = 30 g + 5 g vials, no waste). Bill JW on a separate claim line
for the discarded units when partial-vial waste is unavoidable (most commonly weight-based pediatric
or MMN dosing). Convert waste mg ÷ 500 = JW units. One of JZ or JW must be on every J1569 claim
per CMS's July 2023 single-dose container policy.
What is the Medicare reimbursement for J1569?
For Q2 2026, the Medicare Part B payment limit for J1569 is $49.081 per 500 mg unit (ASP + 6%), or $0.098 per mg. A 35 g (70 unit) dose reimburses at approximately $3,435.67 per infusion. Annualized cost for monthly PI maintenance (12 × 35 g) is approximately $41,228 in drug payment (ASP+6%). Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.
Why does Gammagard Liquid use a 500 mg unit?
CMS standardized on a 500 mg unit basis for the entire IVIG family (J1459, J1554, J1557, J1561, J1566, J1568, J1569, J1572, J1599) because IVIG doses are large — typical PI maintenance is 20–50 g per infusion. A 1 mg unit basis would push unit counts to 5- and 6-digit numbers, breaking claim-form unit-edit logic. The 500 mg unit aligns claim units with grams (1 unit = 0.5 g, 2 units = 1 g).
Are IVIG products interchangeable for billing?
Clinically the IVIG products (Gammagard Liquid, Privigen, Octagam, Gamunex-C, Hizentra SCIG, etc.) are NOT interchangeable from a payer-contracting standpoint. Each has its own HCPCS, ASP, manufacturer rebate, and payer formulary status. Switching a stable patient typically requires a new PA. See the brand interchangeability section for the full product list.
What are the FDA-approved indications?
FDA-approved: (1) Primary humoral immunodeficiency (PI) in adults and pediatric patients ≥2 years (XLA, CVID, SCID, WAS, IgG subclass deficiencies); (2) Multifocal motor neuropathy (MMN) in adults. Off-label: CIDP, secondary immunodeficiency, ITP, GBS, MG — all common but require payer-specific medical-necessity documentation, billed under the same J1569 code.
Reference
Sources & methodology
Every claim on this page is sourced. Methodology and review history below.
Source documents
- DailyMed — GAMMAGARD LIQUID (immune globulin intravenous, human, 10% liquid) Prescribing Information
- Takeda US — product page and patient support
- CMS — Medicare Part B Drug ASP Pricing File
- CMS — HCPCS Level II code set (J1566, J1568, J1569, etc.)
- AAAAI — Primary Immunodeficiency Practice Parameters
- American Academy of Neurology — MMN guideline
- UnitedHealthcare — Medical Benefit Drug Policy: Immune Globulin (IVIG & SCIG)
- Aetna CPB 0206 — Intravenous Immune Globulin (IVIG)
- Cigna Coverage Policy 1218 — Immune Globulin (IVIG / SCIG)
- CMS — Medicare IVIG Home Infusion Benefit (now permanent for PI)
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 (J1569) | Quarterly | Auto-bound to CareCost ASP layer; updates on CMS file release. |
| Payer policies (UHC CPB, Aetna 0206, Cigna 1218, BCBS) | Semi-annual | Manual review against published payer policy documents. |
| HCPCS / CPT / modifier rules + 500 mg unit basis | Annual | Reviewed against CMS HCPCS quarterly files and AMA CPT releases. |
| NDC, vial sizes, dosing, FDA label, indication list | Event-driven | Tied to manufacturer document version + FDA label revision date. |
Reviewer
Pending SME review. This page is staff-authored from primary sources (FDA label, CMS,
Takeda, payer documents — all linked above). Final review by the CareCost editorial team, the CareCost editorial team, is 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 ($49.081 per 500 mg unit). Manufacturer: Takeda OnePath 2026. FDA label verified April 2026. Brand interchangeability matrix covers 13 IVIG/IGSC products. Disambiguation vs Gammagard S/D (J1566) included.
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. The 500 mg unit basis is verified against the CMS HCPCS Level II code set. Indication and dosing verified against the current FDA label and AAAAI / AAN clinical guidelines. We do not paraphrase from billing-software vendor blogs.