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Hizentra (immune globulin SC, 20%) — HCPCS J1559

CSL Behring · 1 g/5 mL, 2 g/10 mL, 4 g/20 mL, 10 g/50 mL single-dose vials (200 mg/mL) · Subcutaneous pump infusion (60–120 min) · Primary immunodeficiency · CIDP maintenance

Hizentra is the leading subcutaneous immune globulin (SCIG), billed under HCPCS J1559 at 100 mg per unit. This is NOT the IVIG 500 mg/unit basis — getting the unit math wrong is the most common Hizentra denial. SC infusion runs via mechanical pump over 60–120 minutes per session, typically weekly at home after patient training. Admin codes are 96369 + 96370 + 96371 (SC pump infusion family) — not 96365/96366 (those are IV). Q2 2026 Medicare reimbursement: $14.515/100 mg unit (~$145/g; $1,451.50 per 10 g weekly dose).

✓ASP data:Q2 2026 (live)
✓Payer policies:verified May 2026
✓Manufacturer guide:CSL Behring 2026
✓FDA label:verified May 2026
✓Page reviewed:

Instant Answer — the 5 things you need to bill J1559

HCPCS
J1559
100 mg = 1 unit (NOT 500 mg)
Typical dose
100 units
10 g weekly SC (PI maintenance)
Modifier
JZ
Single-dose vial, no waste
Admin CPT
96369
+ 96370 / 96371 (SC pump — NOT 96365)
Medicare ASP+6%
$14.515
per 100 mg, Q2 2026 · $1,451.50/10 g
HCPCS descriptor
J1559 — "Injection, immune globulin (Hizentra), 100 mg" 100 mg/unit
Unit basis trap
1 unit = 100 mg of IgG. Different from IVIG (J1459/J1568/J1569 etc.) which use 500 mg/unit. A 10 g (10,000 mg) dose = 100 units of J1559 — not 20 units (IVIG basis), not 10,000 units (per-mg basis).
Indications
Primary humoral immunodeficiency (PI, adults + children ≥2 yr); CIDP maintenance therapy in adults (first FDA-approved SCIG for CIDP, 2018)
Dosing — PI (post-IVIG conversion)
Weekly Hizentra = (prior monthly IVIG dose × 1.37) ÷ 4; typically 100–200 mg/kg per week SC
Dosing — CIDP maintenance
200–400 mg/kg per week SC (after IVIG induction); biweekly equivalent permitted
Frequency options
Weekly (most common), biweekly, or daily (frequent small-volume rapid push) per patient preference
Vials
1 g/5 mL, 2 g/10 mL, 4 g/20 mL, 10 g/50 mL single-dose vials (200 mg/mL = 20% concentration)
Route
Subcutaneous infusion via mechanical pump (typically abdomen, thigh, hip; 1–6 sites simultaneously); 60–120 min per session; rapid-push manual SC injection also FDA-approved
Setting
Home self-administration is the norm after pump training (POS 12); ambulatory infusion (POS 49) and office (POS 11) used during training and for unable-to-self-infuse patients
FDA approval
PI: March 2010; CIDP maintenance: March 2018 (first SCIG with FDA-approved CIDP indication)
Calculate patient estimate → Read full reference Open 1-page cheat sheet
⚠️
UNIT-BASIS TRAP — J1559 = 100 mg per unit, not 500 mg. Hizentra is a SCIG code with a 100 mg/unit basis. It does NOT use the IVIG 500 mg/unit basis (Privigen J1459, Octagam J1568, Gammagard Liquid J1569, Gamunex-C J1561, etc.). A 10 g weekly Hizentra dose bills as 100 units of J1559. Billing it as 20 units (IVIG math) under-reports drug by 5x and triggers an underpayment that auditors will eventually catch. Billing it as 10,000 units (per-mg math) over-reports by 100x and triggers an automatic denial. Verify the unit math on every claim.
⚠️
SC pump admin codes — 96369 / 96370 / 96371, NOT 96365 or 96372. Hizentra is delivered via a small mechanical infusion pump over 60–120 minutes. Use the SC infusion family: 96369 (initial up to 1 hour, includes pump set-up + first SC site), 96370 (each additional hour), and 96371 (additional pump set-up with new SC site, list separately). Do NOT bill 96365/96366 — those are IV therapeutic infusion codes; Hizentra is not IV. Do NOT bill 96372 — that is a one-shot SC injection (think Cosentyx, Stelara), not a pump-driven SCIG infusion.
🏠
Home self-administration is the dominant Hizentra setting. After 1–3 in-clinic training infusions, the overwhelming majority of Hizentra patients self-infuse at home with a portable pump. This drives a medical-benefit (Part B + home-infusion services) vs DME/specialty-pharmacy benefit billing decision that varies by payer. Map the benefit before the first home infusion — see site of care & place of service.
Phase 1 Identify what you're billing SCIG vs IVIG is the first decision; everything downstream changes from there.

SCIG (Hizentra) vs. IVIG — the foundational billing distinction FDA + payer verified May 2026

Same therapeutic class (immune globulin), different molecules in the bottle, very different billing infrastructure.

Immune globulin therapy splits into two delivery routes: intravenous (IVIG — Privigen, Gammagard Liquid, Octagam, Gamunex-C, etc.) and subcutaneous (SCIG — Hizentra, Cuvitru, Cutaquig, Xembify, plus Gamunex-C which is IV+SC dual-approved). They are clinically interchangeable for stable patients with primary immunodeficiency and for CIDP maintenance, but the billing infrastructure differs from the unit basis on up.

Hizentra (SCIG)IVIG (Privigen / Gammagard Liquid / Octagam / Gamunex-C)
HCPCSJ1559J1459 Privigen, J1569 Gammagard Liquid, J1568 Octagam, J1561 Gamunex-C
Unit basis100 mg = 1 unit500 mg = 1 unit
Concentration20% (200 mg/mL)5% or 10% (50 or 100 mg/mL)
RouteSubcutaneous, mechanical pumpIntravenous, gravity or pump
Admin CPT96369 + 96370 + 9637196365 + 96366
Typical session length60–120 minutes2–4 hours (rate titration required)
FrequencyWeekly (or biweekly / daily push)Every 3–4 weeks
Dominant sitePatient home (POS 12) after trainingAmbulatory infusion (POS 49) or hospital outpatient (POS 19/22)
IgG kineticsFlat trough (steady-state)Peaks & troughs (post-infusion peak, pre-next-infusion trough)
Side-effect profileLocal site reactions; very rare systemicHeadache, fever, chills (rate-related); rare TRALI / aseptic meningitis / thrombosis
Clinical advantagesLifestyle flexibility, lower systemic AEs, home-friendlyFaster IgG correction, less frequent admin, better for unstable / loading dose
Payer steerage (UHC, several BCBS)Often preferred for stable PI / CIDPOften required to step through SCIG trial first (chronic stable patients)
Major payer trend (2024–2026): UnitedHealthcare, Aetna, and several BCBS plans have added SCIG-preference language to their immune globulin LCDs. For chronic stable PI or CIDP maintenance, the plan may require a documented SCIG trial (or contraindication) before approving ongoing IVIG. This makes SCIG conversion a routine clinical event — bill the IVIG-to-SCIG transition cleanly (see conversion math).
SCIG-preference does not mean cheaper per gram. Hizentra's per-gram ASP runs higher than most IVIG products (20% concentration premium + delivery convenience). The payer's interest is in eliminating chair time + reducing systemic AE costs — not drug acquisition cost. See Medicare reimbursement for per-gram comparisons.

Dosing & unit math FDA label verified May 2026

From the FDA Hizentra prescribing information (BL 125350).

Primary humoral immunodeficiency (PI) — adults & children ≥2 yr

  • Conversion from IVIG: initial weekly Hizentra dose = (previous monthly IVIG dose × 1.37) ÷ 4. Initiate ~1 week after the last IVIG dose.
  • Maintenance range: typically 100–200 mg/kg per week SC, adjusted to maintain therapeutic IgG trough.
  • Frequency options: weekly (most common), biweekly (2× weekly dose every 2 weeks), or daily ("rapid push" small-volume manual SC).

CIDP maintenance — adults

  • Recommended weekly dose: 200–400 mg/kg per week SC, divided across 1–7 days per week per patient preference.
  • Indication scope: maintenance after IVIG-induced clinical improvement — not for de novo CIDP induction. Document IVIG induction and stabilization in the PA.
  • Approval history: Hizentra became the first SCIG with FDA-approved CIDP maintenance indication in March 2018 (PATH study).

Worked example — PI patient on 10 g/week (typical adult ~70 kg, 140 mg/kg)

# Per-infusion (weekly)
Drug mg per dose: 10,000 mg (10 g)
Drug units billed (J1559): 100  # 10,000 ÷ 100 mg/unit
HCPCS: J1559 · Modifier: JZ
Vials: 1 × 10 g/50 mL single-dose vial (or 2 × 4 g + 1 × 2 g, etc.)
Admin: 96369 (initial 1 hr, pump set-up + first SC site)
+ 96370 (each additional hour, if infusion runs >60 min)
+ 96371 (additional pump set-up + new SC site, if 2 sites used)

# Year-1 totals (52 weekly infusions)
Total drug units billed: 5,200 (52 × 100)
Total drug cost (Q2 2026 ASP+6%): ~$75,478 before sequestration

Vial size to dose mapping

Patient size / weekly doseVial combination (1 of many)Total mgUnits billed
~50 kg / 5 g weekly1 × 4 g + 1 × 1 g5,000 mg50 units
~70 kg / 8 g weekly2 × 4 g8,000 mg80 units
~70 kg / 10 g weekly1 × 10 g10,000 mg100 units
~85 kg / 12 g weekly1 × 10 g + 1 × 2 g12,000 mg120 units
CIDP / ~70 kg / 20 g weekly2 × 10 g20,000 mg200 units
Round to vial size; bill mg actually drawn. Hizentra's 200 mg/mL concentration means small mg differences map to small mL differences. Choose the vial combination that minimizes waste; bill the mg administered, not the mg ordered. Use JW for any discarded portion of a single-dose vial.

IVIG → SCIG conversion (the 1.37 factor) FDA label verified May 2026

The single most-asked question when transitioning a stable PI patient from IVIG to Hizentra.

SCIG bioavailability and trough kinetics differ from IV. The Hizentra label specifies a conversion coefficient of 1.37 applied to the prior monthly IVIG dose, then divided across the weekly SCIG schedule:

# Hizentra weekly dose calculation
Weekly Hizentra dose (g) = (Previous monthly IVIG dose (g) × 1.37) ÷ 4

# Examples
20 g monthly IVIG → (20 × 1.37) ÷ 4 = 6.85 g weekly  → round to 7 g
30 g monthly IVIG → (30 × 1.37) ÷ 4 = 10.275 g weekly  → round to 10 g
40 g monthly IVIG → (40 × 1.37) ÷ 4 = 13.7 g weekly  → round to 14 g

# Schedule transitions
Initiate Hizentra ~1 week after the last IVIG dose
Biweekly equivalent: 2 × the weekly dose every 2 weeks
Daily push equivalent: weekly dose ÷ 7, infused in small volumes daily

What changes on the claim during conversion

ElementBefore (IVIG)After (Hizentra)
HCPCSJ1459 / J1568 / J1569 / J1561 (etc.)J1559
Unit basis500 mg / unit100 mg / unit
Admin CPT96365 (initial) + 96366 (additional hour)96369 + 96370 + 96371
FrequencyEvery 3–4 weeksWeekly (or biweekly / daily)
Site of careOften AIC (POS 49) or HOPD (POS 19/22)Often home (POS 12) after training
AuthorizationIVIG PASubmit new PA for SCIG (most payers)
Submit a new PA at conversion. Even if the same diagnosis is on file, the SCIG product is a separate authorization. Include: prior IVIG regimen, IgG trough on IVIG, conversion calculation, anticipated weekly SCIG dose, and training/home-infusion plan.

NDC & vial reference FDA NDC Directory verified May 2026

NDC (10-digit)Vial sizeVolumeConcentration
44206-0451-011 g5 mL200 mg/mL (20%)
44206-0452-022 g10 mL200 mg/mL (20%)
44206-0454-044 g20 mL200 mg/mL (20%)
44206-0455-1010 g50 mL200 mg/mL (20%)
All Hizentra vials are single-dose (single-dose container per CMS terminology). JZ modifier applies on every claim with no waste; JW applies if any portion of a vial is discarded. NDCs above are the carton/package NDCs distributed by CSL Behring; verify against the FDA NDC Directory if a payer requests an alternate format. Convert to 11-digit format by inserting the leading zero in the labeler segment if needed (e.g., 44206-0451-01 → 44206-0451-01; CSL labeler is already 5 digits).
Stabilizer: Hizentra is L-proline stabilized (not glycine, sucrose, sorbitol, or maltose). Patients with renal disease, diabetes, or hyperprolinemia syndromes may need a different IG product — document the clinical rationale if Hizentra is selected over an alternative SCIG.
Phase 2 Code the claim SC pump infusion family (96369/96370/96371) — not IV, not single-shot SC injection.

Administration codes (96369 / 96370 / 96371) CPT verified May 2026

SC pump infusion family. The most common Hizentra admin error is using IV codes (96365/96366) or single-shot SC injection (96372).

CodeDescriptorWhen to use for Hizentra
96369 Subcutaneous infusion for therapy or prophylaxis (specify substance or drug); initial, up to 1 hour, including pump set-up and establishment of subcutaneous infusion site(s) Primary code for Hizentra. Bill once per session. Includes pump priming and the first SC site.
96370 Subcutaneous infusion for therapy or prophylaxis (specify substance or drug); each additional hour (list separately in addition to code for primary procedure) For sessions running >60 minutes (most adult Hizentra infusions). Bill per additional hour (or substantial fraction).
96371 Subcutaneous infusion for therapy or prophylaxis (specify substance or drug); additional pump set-up with establishment of new subcutaneous infusion site(s) (list separately in addition to code for primary procedure) When a second pump is added or a new SC infusion site is established mid-session (large doses across multiple body sites). Add-on, not standalone.
96365 / 96366 Therapeutic IV infusion (initial / each additional hour) NOT appropriate for Hizentra. These are IV codes; Hizentra is SC.
96372 Therapeutic SC or IM injection (specify substance or drug) NOT appropriate for Hizentra. 96372 is a single-shot manual injection (e.g., Cosentyx, Stelara, B12). Hizentra is a pump-driven infusion, even on rapid push.
Top admin-code denial pattern: Provider-side billing systems sometimes auto-populate 96365 (IV therapeutic) for any immune globulin claim. For SCIG products (Hizentra, Cuvitru, Cutaquig, Xembify, HyQvia), override to 96369/96370/96371. Audit Hizentra claims monthly to catch this drift.
Home self-administration: When the patient self-infuses at home, the home-infusion provider bills the per-diem and supplies (S9338 / S9494 / S9559 family or 99601/99602 nursing visits when a nurse is present). The drug J1559 and the 96369/96370/96371 admin codes are typically billed by the infusion provider on the same claim under the medical benefit. See home administration billing.

Modifiers CMS verified May 2026

JZ — required on every Hizentra claim with no waste

Effective July 1, 2023, CMS requires the JZ modifier on every single-dose container claim when no drug is discarded. All Hizentra vials are single-dose containers. JZ applies on the majority of Hizentra claims when the dose maps cleanly to vial sizes (1 g, 2 g, 4 g, 10 g).

JW — partial-vial waste

JW reports the discarded portion of a single-dose vial. For Hizentra, JW applies whenever the dose does not map cleanly to the available vial sizes. Example: a 6 g weekly dose — 1 × 4 g + 1 × 2 g with no waste = JZ. But if a patient receives 8.5 g and the closest combination is 1 × 10 g (1.5 g discarded) or 2 × 4 g + 1 × 1 g (0.5 g discarded), the discarded mg are reported on a separate JW line. One of JZ or JW must be on every J1559 claim line.

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 a Hizentra training infusion. Pump training visits routinely justify a modifier-25 E/M.

340B modifiers (JG, TB)

For 340B-acquired Hizentra, follow your MAC's current 340B modifier policy. CSL Behring's billing guide does not provide 340B-specific guidance.

ICD-10-CM by indication FY2026 verified May 2026

Use the most specific code supported by encounter documentation. PI requires IgG-level evidence; CIDP requires neuro evaluation.

IndicationICD-10 familyDocumentation requirements
Common variable immunodeficiency (CVID)D83.0 – D83.9IgG < 5 g/L (or LCD-specified threshold), poor vaccine response, recurrent infections
Hypogammaglobulinemia (unspecified)D80.1IgG levels, infection history
Selective IgG subclass deficiencyD80.3Subclass quantification + functional antibody response
X-linked agammaglobulinemia (Bruton)D80.0BTK gene confirmation; pediatric onset
Selective IgA deficiencyD80.2Generally NOT an SCIG indication on its own (asymptomatic IgA deficiency is monitored, not treated)
Other immunodeficiency w/ predominantly antibody defectsD80.8 / D80.9Documentation of antibody defect + clinical infections
Combined immunodeficiencyD81.xSCID and variants; usually pediatric
Immunodeficiency w/ other major defectD82.xWiskott-Aldrich (D82.0), DiGeorge (D82.1), etc.
CIDP maintenanceG61.81Neuro evaluation, EMG/NCV, IVIG induction documented; first SCIG with FDA-approved CIDP indication (March 2018)
PI documentation is LCD-driven. Most MACs require: (1) IgG level below the LCD threshold, (2) poor specific antibody response to vaccine challenge (pneumococcal, tetanus), and (3) clinical history of recurrent serious infections. PI without IgG-level documentation is a routine denial. The same is true commercially — UHC, Aetna, Cigna, and BCBS plans typically require these three elements.
CIDP maintenance billing requires IVIG induction documentation. Hizentra's CIDP indication is for maintenance after IVIG-induced clinical improvement — not for de novo CIDP. The PA must include the IVIG induction regimen, the clinical response, and a justification for transition to SC maintenance.

Site of care & place of service Verified May 2026

Hizentra's site-of-care distribution is the inverse of IVIG: home (POS 12) is dominant, with ambulatory infusion (POS 49) and physician office (POS 11) used during the initial training period or for patients unable to self-infuse. Hospital outpatient (POS 19/22) is rarely justified for routine Hizentra and is the most common site-of-care denial.

SettingPOSClaim formTypical use for Hizentra
Patient home (self-infusion)12CMS-1500 / 837P (medical benefit) or pharmacy claimDominant setting after training. 80%+ of stable Hizentra patients.
Patient home (RN-administered)12CMS-1500 / 837P with 99601/99602 nursing visitsPatients who cannot self-infuse; intermittent RN visits
Ambulatory infusion suite (AIC)49CMS-1500 / 837PInitial training (1–3 sessions); ongoing if patient can't self-infuse
Physician office11CMS-1500 / 837PTraining; same-day E/M with infusion
Oncology / specialty clinic11 / 49CMS-1500 / 837PFor patients managed through immunology / hem-onc clinic infrastructure
Hospital outpatient (on-campus)22UB-04 / 837IRarely justified. Common site-of-care denial.
Hospital outpatient (off-campus PBD)19UB-04 / 837IRarely justified. Common site-of-care denial.
Site-of-care comparison vs IVIG: Where IVIG is steered into ambulatory and home infusion out of hospital outpatient, Hizentra is steered into home from any other setting. The payer logic: SCIG is designed for home self-administration, so any clinical setting (including AIC) is only justified during training or for patients with documented inability to self-infuse.

Home administration billing CMS Home Infusion Therapy verified May 2026

Hizentra is the canonical home-infused biologic. The medical-benefit vs DME/specialty-pharmacy decision is the largest reimbursement variable.

Two coverage pathways

Medical benefit (Part B / commercial medical)Pharmacy / DME benefit
Drug billJ1559 on CMS-1500 / 837P from home-infusion providerNDC-based pharmacy claim from specialty pharmacy; no J1559
Admin codes96369 + 96370 + 96371 when infused with provider involvementNone — patient self-administered; supply only
Per-diem servicesS9338 (infusion therapy, immune globulin, per-diem) and related S-codesBundled into specialty pharmacy supply fee
Nursing visits (when applicable)99601 (initial home infusion visit, up to 2 hr) / 99602 (each additional hour)Not billed under pharmacy benefit
Pump & suppliesOften bundled into S-code per-diemBundled into specialty pharmacy fee or billed under DME
Typical payerMedicare Part B; commercial medical plans w/ home-infusion benefitSome commercial plans for stable self-administered SCIG; limited Medicare role
Patient cost-shareMedical deductible + coinsurance (often 20% pre-Medigap)Pharmacy copay tier (specialty)

Medicare Part B SCIG coverage

  • Medicare Part B covers Hizentra plus home-infusion services for PI under the SCIG demonstration / Home Infusion Therapy Services benefit (DME MAC jurisdiction historically; transitioning under the 21st Century Cures Act home-infusion framework).
  • CIDP home-infusion coverage under Part B is generally accepted when the drug is prescribed and infused per FDA labeling.
  • Verify your DME MAC's current Hizentra LCD before submitting (Noridian, CGS, Palmetto, NHIC).

Commercial home-infusion pathway

  • Most commercial plans cover Hizentra under the medical benefit with a contracted home-infusion provider (Coram / CVS Health, Option Care Health, Optum Infusion, BriovaRx, etc.).
  • Some plans require step therapy through the pharmacy benefit specialty pharmacy first — verify per plan.
  • UHC, Aetna, Cigna, and BCBS plans generally pre-authorize the home-infusion provider as part of the Hizentra PA.
The most common home-infusion billing error: billing the per-diem (S9338) without the drug (J1559), or vice versa. Both lines must be on the claim — payer reconciles the per-diem to the underlying drug administration. Missing either line triggers automatic denial.
Pump and supplies: The mechanical infusion pump used for Hizentra (commonly the CRONO-S, Freedom60, or Eitan equivalent) is typically supplied by the home-infusion provider or DME supplier. Most commercial and Medicare home-infusion benefits bundle the pump and tubing/needle supplies into the per-diem rate. Itemized DME billing for the pump (E0784 or similar) is rarely appropriate when the per-diem is billed.

Claim form field mapping CSL Behring billing guide 2026

InformationCMS-1500 boxNotes
NPI17b / 24JRendering provider (or home-infusion provider's NPI)
NDC qualifier + 11-digit NDC + UoM + qty24A shaded areaN4 + 11-digit Hizentra NDC + ML + total volume in mL
HCPCS J1559 + JZ (or JW for waste)24D (drug line)One of JZ or JW required on every claim
Drug units24Gmg administered ÷ 100 (e.g., 10,000 mg = 100 units)
CPT 96369 (admin line, primary)24D (admin line)Initial up to 1 hr SC infusion + pump set-up + first SC site
CPT 96370 (admin line, addl hour)24D (additional admin line)Each additional hour beyond 60 min; list separately
CPT 96371 (addl pump set-up)24D (additional admin line)Additional pump or new SC site, list separately
S9338 (per-diem home infusion)24D (services line)For home-infusion provider claims (medical benefit)
99601 / 99602 (nursing visits)24DWhen RN administers (not patient self-infusion)
ICD-1021D80.x / D81.x / D82.x for PI; G61.81 for CIDP maintenance
PA number23Required by all major payers for SCIG
Phase 3 Get paid PA documentation: IgG levels (PI), neuro/IVIG induction (CIDP), training plan.

Payer LCDs & PA criteria Reviewed May 2026

All major payers PA SCIG. UHC and several BCBS plans actively prefer SCIG over IVIG for stable PI / CIDP.

PayerPA?Key criteriaSCIG-vs-IVIG positioning
UnitedHealthcare
SCIG / Immune Globulin medical policy		 Yes PI: IgG level + vaccine challenge + recurrent infections. CIDP: IVIG induction documented + neuro eval. Training plan + home-infusion provider authorized at PA. Often SCIG-preferred for stable chronic patients; IVIG may require step through SCIG trial
Aetna
CPB Immune Globulin		 Yes Indication-specific criteria mirror UHC; CIDP requires documented IVIG induction. Site-of-care prefers home or AIC for SCIG. Generally allows clinician choice; some plans steer to SCIG for stable chronic
Cigna
Coverage Policy 1006 (Immune Globulin)		 Yes PI / CIDP standard criteria; home-infusion benefit detailed in policy SCIG and IVIG covered at parity for stable patients
BCBS plans
Vary by plan		 Yes Generally aligned with FDA label and major commercial peer policies Plan-specific; many plans now SCIG-preferred for chronic stable
Medicare (Part B)
DME MAC SCIG LCD + Home Infusion Therapy Services		 Often (DME) PI is well-covered; CIDP coverage at home requires medically necessary documentation per Cures Act home-infusion framework Coverage parity; clinical choice driven by patient/clinician

PA documentation checklist (PI)

  • IgG level (LCD-specific threshold, often < 5 g/L or < 500 mg/dL)
  • Specific antibody response to vaccine challenge (pneumococcal polysaccharide, tetanus toxoid)
  • Recurrent serious infection history (otitis, sinusitis, pneumonia, etc.) with treatment dates
  • Conversion calculation if transitioning from IVIG (1.37 factor)
  • Home-infusion training plan + designated provider (commercial)

PA documentation checklist (CIDP maintenance)

  • Neurologist evaluation + EMG/NCV consistent with CIDP
  • IVIG induction regimen + documented clinical improvement
  • Justification for SC maintenance (lifestyle, vascular access, AE profile, etc.)
  • Anticipated weekly Hizentra dose (200–400 mg/kg per week range)

Medicare reimbursement CMS Q2 2026 (live)

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

Q2 2026 payment snapshot — J1559

Effective April 1 – June 30, 2026 · 1 unit = 100 mg

ASP + 6%
$14.515
per 100 mg unit (~$0.145/mg)
10 g weekly dose
$1,451.50
100 units × ASP+6%
Per gram
$145.15
10 units (1 g) × ASP+6%
Annualized cost: 10 g weekly × 52 weeks = ~$75,478/year (Medicare ASP+6%) for a typical 70 kg PI patient at 140 mg/kg/week. Larger patients or CIDP-dose regimens (200–400 mg/kg/week) scale proportionally. After ~2% sequestration: ~$73,950/year actual paid.

Per-gram comparison vs IVIG

  • Hizentra (J1559): ~$145/g (Q2 2026)
  • Privigen (J1459): typically ~$70–$80/g
  • Gammagard Liquid (J1569): typically ~$70–$85/g
  • Octagam (J1568): typically ~$60–$75/g
  • Gamunex-C (J1561): typically ~$70–$80/g

Hizentra runs roughly 2× the per-gram price of standard IVIG products due to the 20% concentration manufacturing premium and self-administration convenience. Total cost of care comparison favors SCIG once chair time, nursing time, and AE costs are included — which is why payers actively prefer SCIG for stable chronic patients despite the per-gram drug premium.

Coverage

No NCD specific to Hizentra. Coverage falls under MAC LCDs for SCIG (immune globulin subcutaneous) and the Home Infusion Therapy Services benefit. All MACs cover J1559 for FDA-approved on-label indications (PI and CIDP maintenance) with appropriate ICD-10 and clinical documentation.

Patient assistance — CSL Behring AssureSupport CSL verified May 2026

  • CSL Behring AssureSupport (Hizentra): 1-877-355-IGIV (1-877-355-4448) — benefits investigation, prior authorization assistance, appeal support, training resources
  • Hizentra Co-Pay Assistance Program: commercial copay support for eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients)
  • CSL Behring Patient Assistance Program: free product for uninsured / underinsured patients meeting income requirements
  • Independent foundations for Medicare patients: PAN Foundation (immunodeficiency / CIDP funds), HealthWell Foundation, Patient Advocate Foundation — verify open funds quarterly
  • IDF (Immune Deficiency Foundation): primaryimmune.org — patient education, advocacy, resources
  • GBS|CIDP Foundation: gbs-cidp.org — CIDP patient education and support
  • Web: hizentra.com / cslbehring.com
Need to model what a specific Hizentra patient will actually pay after copay assistance, deductible, coinsurance, and OOP max? Run a CareCost Estimate — J1559 pre-loaded.

SCIG brand interchangeability Verified May 2026

SCIG products are NOT interchangeable for billing. Each brand has its own HCPCS, NDC, ASP, and concentration. Match the code to the product actually infused.

HCPCSBrandMfrConcentrationStabilizerUnit basisFDA-approved indications
J1559 Hizentra CSL Behring 20% liquid SC L-proline 100 mg PI (adult + ped ≥2); CIDP maintenance (adult)
J1555 Cuvitru Takeda 20% liquid SC Glycine 100 mg PI (adult + ped ≥2)
J1551 Cutaquig Octapharma 16.5% liquid SC Maltose 100 mg PI (adult + ped ≥2)
J1558 Xembify Grifols 20% liquid SC Glycine 100 mg PI (adult + ped ≥2)
J1575 HyQvia Takeda 10% IG + recombinant hyaluronidase Glycine 100 mg IG (per HCPCS) PI; CIDP maintenance (adult, 2024) — facilitated SC, monthly dosing possible
J1561 Gamunex-C Grifols 10% liquid (IV or SC use) Glycine 500 mg (IV basis applies even when given SC) PI (IV/SC), ITP (IV), CIDP (IV)
IVIG companion class (500 mg unit basis, IV admin codes 96365/96366):
J1459 Privigen CSL Behring 10% liquid IV L-proline 500 mg PI, ITP, CIDP
J1569 Gammagard Liquid Takeda 10% liquid IV Glycine 500 mg PI, MMN
J1568 Octagam (5% & 10%) Octapharma 5% / 10% liquid IV Maltose 500 mg PI; chronic ITP; dermatomyositis (10%)
Three brand-related billing patterns to avoid:
  • Wrong code, right route: billing J1559 (Hizentra) for a patient who actually received Cuvitru (J1555) or Xembify (J1558) is a denial trigger and a compliance issue. ASP differences create a $/unit delta auditors will catch.
  • Wrong unit basis when crossing routes: applying the IVIG 500 mg/unit basis to a SCIG product (or vice versa) under-reports or over-reports the dose by 5×. The most common crossover error is on Gamunex-C (J1561) when given SC — it still uses the 500 mg/unit basis because the HCPCS is the IV code.
  • Right code, payer-mandated different brand: some payers contract preferentially with specific SCIG brands. UHC may steer to Hizentra on one PA while Aetna may require Xembify or Cuvitru on the next. Verify the payer's preferred SCIG brand on every PA; do not assume continuity across payers.

When clinical brand justification is needed

  • Diabetes / renal: avoid maltose-stabilized SCIG (Cutaquig) due to interference with some glucose monitors and renal precautions; Hizentra (proline) and Cuvitru/Xembify (glycine) preferred.
  • Hyperprolinemia: avoid proline-stabilized products (Hizentra, Privigen); prefer glycine (Cuvitru, Xembify, Gammagard Liquid) or maltose (Cutaquig).
  • Tolerability history: if the patient had local site reactions on one SCIG brand, switching to another stabilizer/concentration combination is a common clinical strategy — document the rationale.
  • Monthly dosing preference: consider HyQvia (J1575) which uses recombinant hyaluronidase to enable larger-volume monthly SC infusions vs the weekly Hizentra schedule.
Phase 4 Fix problems Unit math, IV-vs-SC admin code confusion, and missing PA documentation are the top three.

Common denials & how to fix them

Denial reasonCommon causeFix
Unit math wrong (under by 5x)IVIG 500 mg/unit basis applied to J1559Recalculate: J1559 = 100 mg/unit. 10 g = 100 units. Resubmit corrected.
Unit math wrong (over by 100x)1 mg/unit (per-mg) basis applied; 10,000 units submitted for 10 gRecalculate: J1559 = 100 mg/unit. 10 g = 100 units. Resubmit corrected.
Wrong admin code (96365)IV therapeutic code billed instead of SC pump infusionResubmit with 96369 (initial) + 96370 (each addl hour) + 96371 (addl pump set-up if used).
Wrong admin code (96372)Single-shot SC injection code billed instead of pump infusionResubmit with 96369 + 96370 + 96371. 96372 is for one-time SC injections (Cosentyx, Stelara, B12), not pump-driven SCIG.
JZ/JW missingSingle-dose container claim without modifierResubmit with JZ if no waste, JW with discarded units if partial vial.
PI dx without IgG documentationD80.x submitted without IgG level, vaccine challenge, or infection historySubmit complete LCD-required documentation and request retroactive PA.
CIDP without IVIG induction documentedG61.81 submitted with no IVIG induction historyHizentra CIDP is for maintenance after IVIG-induced improvement. Submit IVIG induction regimen + clinical response documentation.
Site of care (HOPD)Hizentra billed from POS 19/22 outside of training periodMove to home (POS 12), AIC (POS 49), or office (POS 11). Document medical necessity if HOPD truly required.
Per-diem without drug or vice versaS9338 billed without J1559 (or J1559 without S-code on home claim)Both lines required on home-infusion claims. Resubmit complete claim.
SCIG not preferred brandHizentra billed when payer requires Xembify / Cuvitru / CutaquigVerify formulary; switch product or submit non-formulary exception with clinical justification.
No new PA at IVIG → SCIG conversionOld IVIG PA used for new Hizentra claimSubmit fresh PA with conversion calculation, training plan, and home-infusion provider designation.

Frequently asked questions

What is the HCPCS code for Hizentra and what is the unit basis?

Hizentra is billed under HCPCS J1559 — "Injection, immune globulin (Hizentra), 100 mg." Each 100 mg of IgG equals one billable unit. This is NOT the IVIG 500 mg/unit basis used by J1459, J1568, J1569, J1561, etc., and it is NOT a per-mg basis. A 10 g (10,000 mg) weekly dose bills as 100 units of J1559.

What administration CPT codes do I use for Hizentra?

Use 96369 (subcutaneous infusion, initial up to 1 hr, including pump set-up and first SC site) for the primary code, plus 96370 (each additional hour) for sessions running >60 min, and 96371 (additional pump set-up + new SC site) when a second pump or site is initiated. Do NOT bill 96365/96366 (those are IV) and do NOT bill 96372 (that is a single-shot SC injection, not a pump infusion).

How does Hizentra differ from IVIG products like Privigen, Gammagard Liquid, or Octagam?

Hizentra is subcutaneous — pump-infused under the skin over 60–120 min, typically weekly, overwhelmingly self-administered at home. IVIG products go intravenously over 2–4 hours every 3–4 weeks. Billing differs entirely: 100 mg/unit vs 500 mg/unit, SC pump admin codes vs IV admin codes, home-dominant POS vs ambulatory/HOPD POS. UHC and several BCBS plans actively prefer SCIG over IVIG for stable chronic patients. See the SCIG vs IVIG comparison.

How do I convert a monthly IVIG dose to a weekly Hizentra dose?

Per the FDA Hizentra label: weekly Hizentra dose = (previous monthly IVIG dose × 1.37) ÷ 4. The 1.37 factor accounts for differences in bioavailability and trough kinetics between IV and SC routes. Example: 30 g IVIG monthly converts to (30 × 1.37) ÷ 4 = 10.275 g weekly Hizentra, rounded to 10 g per week. Initiate Hizentra ~1 week after the last IVIG dose. See the conversion section.

What is the Medicare reimbursement for J1559?

For Q2 2026, the Medicare Part B payment limit for J1559 is $14.515 per 100 mg unit (ASP + 6%), or roughly $145 per gram. A 10 g weekly dose bills as 100 units and reimburses at $1,451.50 per infusion. Annualized at 52 weekly infusions: ~$75,478/year for a 10 g/week patient. Sequestration (~2%) reduces actual paid to roughly ASP + 4.3%.

Is Hizentra billed as a medical benefit or a pharmacy/DME benefit when self-administered at home?

Both pathways exist. Medical benefit (Part B / commercial medical): bill J1559 + 96369/96370/96371 + S9338 per-diem from the home-infusion provider on a CMS-1500/837P. Pharmacy/specialty: NDC-based pharmacy claim with no J1559 line. Medicare Part B typically covers Hizentra plus home-infusion services for PI under the SCIG demonstration / Home Infusion Therapy Services benefit. Verify per payer — UHC, Aetna, BCBS, and Medicare DME MACs all have product-specific home-infusion policies. See home administration billing.

What ICD-10 codes support Hizentra coverage?

For PI: D80.x (immunodeficiency w/ predominantly antibody defects, e.g., D80.0 X-linked, D80.1 hypogamma, D80.3 IgG subclass, D83.x CVID family), D81.x (combined immunodeficiencies), D82.x (immunodeficiency with other major defects). For CIDP maintenance: G61.81. CIDP requires documented IVIG induction prior to SC maintenance per FDA label.

What other SCIG products compete with Hizentra and how do they bill differently?

Cuvitru (Takeda, J1555, 20% glycine), Cutaquig (Octapharma, J1551, 16.5% maltose), Xembify (Grifols, J1558, 20% glycine), and HyQvia (Takeda, J1575, 10% IG + hyaluronidase — enables monthly dosing). Gamunex-C (Grifols, J1561) is approved for both IV and SC use; when given SC it still bills under J1561 with the 500 mg/unit basis (because the HCPCS is the IV code). See the SCIG brand matrix.

Reference Sources & methodology Every claim on this page is sourced. Methodology and review history below.

Source documents

  1. FDA — Hizentra (Immune Globulin Subcutaneous, Human, 20% Liquid)
    FDA-approved product page; PI March 2010, CIDP maintenance March 2018
  2. CSL Behring — Hizentra Prescribing Information (FDA label)
    Includes IVIG-to-SCIG conversion math (1.37 factor), PI/CIDP dosing, vial/concentration data
  3. Hizentra HCP & patient site — CSL Behring
    Coding, billing, and home-infusion resources for Hizentra
  4. CMS — Medicare Part B Drug ASP Pricing File
    Q2 2026 quarterly file, effective April 1 – June 30, 2026
  5. CMS — Home Infusion Therapy Services (21st Century Cures Act framework)
  6. Immune Deficiency Foundation (IDF)
    Patient-facing PI education, advocacy, and IG therapy resources
  7. GBS|CIDP Foundation International
    CIDP patient education and IG therapy resources
  8. AAAAI — Use of Human Immunoglobulin Practice Parameter
    Joint Task Force PI / IG therapy guideline; covers SCIG selection criteria
  9. UnitedHealthcare — Immune Globulin / SCIG Medical Policy
  10. Aetna — CPB Immune Globulin
  11. Cigna — Coverage Policy 1006 (Immune Globulin)
  12. FDA National Drug Code Directory (Hizentra NDCs)

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

ElementCadenceHow it's refreshed
Medicare ASP pricingQuarterlyAuto-bound to CareCost ASP layer; updates on CMS file release.
Payer policies (UHC, Aetna, Cigna, BCBS)Semi-annualManual review against published payer immune globulin / SCIG medical policies.
HCPCS / CPT / modifier rulesAnnualReviewed against CMS HCPCS quarterly files and AMA CPT releases.
NDC, dosing, FDA label, indicationEvent-drivenTied to CSL Behring document version + FDA label revision date.
SCIG brand matrixSemi-annualReviewed against current FDA-approved SCIG product list and HCPCS file.

Reviewer

Pending SME review. This page is staff-authored from primary sources (FDA, CMS, CSL Behring, 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, especially the unit-basis math and SC vs IV admin code selection.

Change log

  • — Initial publication. ASP data: Q2 2026. Manufacturer source: CSL Behring 2026. FDA label: PI March 2010, CIDP maintenance March 2018. Cross-referenced with Privigen, Gammagard Liquid, Octagam (IVIG companions) and Cuvitru, Cutaquig, Xembify, HyQvia (SCIG companions).

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 policy documents. Indication, dosing, and conversion math are verified against the current FDA Hizentra label. We do not paraphrase from billing-software vendor blogs.

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