HCPCS
J9333
1 mg = 1 unit
Phase 1
Identify what you're billing
Confirm Rystiggo (J9333) vs Vyvgart (J9332) and patient antibody serology (AChR vs MuSK).
FcRn class — J9333 (Rystiggo) vs J9332 (Vyvgart / Vyvgart Hytrulo) CMS HCPCS verified May 2026
Same mechanism (FcRn blockade); two molecules; different labeled antibody populations.
Neonatal Fc receptor (FcRn) blockade is a 2021–2023 mechanism for autoantibody-driven autoimmunity.
By preventing FcRn-mediated recycling of IgG in vascular endothelium, FcRn inhibitors accelerate
catabolism of all circulating IgG (including pathogenic autoantibodies) by ~60–70% per treatment
cycle, with recovery between cycles. Two FcRn-targeting biologics are FDA-approved for generalized
myasthenia gravis: Vyvgart / Vyvgart Hytrulo (efgartigimod alfa / efgartigimod
alfa-fcab, J9332, argenx, FDA-approved December 2021 IV / June 2023 SC) and
Rystiggo (rozanolixizumab-noli, J9333, UCB, FDA-approved June 2023).
| Rystiggo (J9333) | Vyvgart / Vyvgart Hytrulo (J9332) | |
|---|---|---|
| Active ingredient | Rozanolixizumab-noli (full-length IgG4 mAb) | Efgartigimod alfa (human IgG1 Fc fragment) ± hyaluronidase (Hytrulo SC) |
| Manufacturer | UCB, Inc. | argenx |
| FDA approval (gMG) | June 26, 2023 | Dec 17, 2021 (IV) / June 20, 2023 (Hytrulo SC) |
| Route | SC infusion (~15 min) | IV (1 hr) or SC injection (Hytrulo, 30–90 sec) |
| Weight-based dose | 7 mg/kg SC weekly × 6 | IV: 10 mg/kg weekly × 4; Hytrulo: fixed 1,008 mg SC weekly × 4 |
| Cycle length | 6 weeks; repeat per clinical response | 4 weeks; repeat per clinical response |
| AChR+ gMG | Yes | Yes |
| MuSK+ gMG | Yes — only labeled FcRn option | NO |
| Seronegative gMG | NOT approved | NOT approved |
| Other indications | None (gMG only) | CIDP (Vyvgart Hytrulo, June 2024) |
| REMS | None | None |
| Setting | Office, AIC, HOPD, stable patients eligible home SC | Office, AIC, HOPD; Hytrulo SC supports home admin |
Coverage gate is the antibody type, not the brand preference. If your patient is
MuSK-antibody positive, Rystiggo is the only labeled FcRn option — Vyvgart will be denied as
off-label. If AChR-positive, either agent is potentially appropriate and payer preference (often via
cost-effective contracting) will determine first-line. Always pull and submit the antibody panel result
with the initial PA.
FcRn vs complement (C5) inhibitors for gMG. Complement inhibitors
(Soliris J1299, Ultomiris J1303) are
continuous IV therapies (q2wk or q8wk) for AChR-positive gMG only, with mandatory Alexion REMS for
meningococcal infection risk. FcRn inhibitors (Rystiggo J9333, Vyvgart J9332) are cyclic SC/IV
therapies without REMS, with Rystiggo uniquely covering MuSK+. Many neurologists trial FcRn first
(lower risk profile, cyclic dosing) and reserve complement inhibitors for refractory AChR+ disease.
Dosing & unit math FDA label verified May 2026
From the FDA-approved Rystiggo prescribing information (BLA 761286). Weight-based with vial-multiple rounding.
Per-cycle dosing schedule
| Element | Specification |
|---|---|
| Dose | 7 mg/kg subcutaneously once weekly |
| Doses per cycle | 6 (one weekly dose for 6 consecutive weeks) |
| Infusion duration | ~15 minutes via SC infusion pump (abdomen or thigh) |
| Site rotation | Alternate abdomen / thigh; do not inject into bruised, tender, or scarred skin |
| Repeat cycle | Based on clinical evaluation; no sooner than day 63 from prior cycle start |
| Vial rounding | Round calculated mg to nearest combination of 280 mg + 140 mg vials per FDA label dosing table |
| Maximum dose per week | 840 mg per FDA label (effectively caps a 120+ kg patient at 840 mg/dose) |
FDA-label vial rounding table (weight band → per-dose mg)
| Body weight | Per-dose mg (rounded) | Vials used | J9333 units / week |
|---|---|---|---|
| < 50 kg | 280 mg | 1 × 280 mg | 280 |
| 50 to < 70 kg | 420 mg | 1 × 280 mg + 1 × 140 mg | 420 |
| 70 to < 100 kg | 560 mg | 2 × 280 mg | 560 |
| ≥ 100 kg | 840 mg | 3 × 280 mg | 840 |
Two approaches to dosing — verify your protocol. Some institutions follow strict
7 mg/kg per actual body weight (resulting in routine partial-vial waste) and others follow the FDA-label
weight-band rounding table (no waste). Per-mg ASP reimbursement applies in both cases. Bill the
actual mg administered (not the calculated 7 mg/kg target) on the primary line; bill
any discarded mg on the JW line. Confirm your facility's standing protocol before assuming either method.
Worked example — 70 kg patient, strict 7 mg/kg
# Calculate dose
Dose: 7 mg/kg × 70 kg = 490 mg
Vials drawn: 2 × 280 mg = 560 mg
Discarded: 560 − 490 = 70 mg (single-dose vial waste)
# Per-dose drug claim lines
Line 1 (administered): J9333 · 490 units · no JZ when JW present
Line 2 (waste): J9333 · 70 units · modifier JW
# Per-dose admin claim line
96372 (SC therapeutic injection) · 1 unit
# Per-dose reimbursement (Q2 2026)
Total: 560 units × $23.396 = $13,101.76 (administered + waste, both reimbursable)
# Per cycle (6 weekly doses)
Drug units: 6 × 560 = 3,360 units
Drug reimbursement: 3,360 × $23.396 = $78,610.56
Admin codes: 6 × 96372
Dose: 7 mg/kg × 70 kg = 490 mg
Vials drawn: 2 × 280 mg = 560 mg
Discarded: 560 − 490 = 70 mg (single-dose vial waste)
# Per-dose drug claim lines
Line 1 (administered): J9333 · 490 units · no JZ when JW present
Line 2 (waste): J9333 · 70 units · modifier JW
# Per-dose admin claim line
96372 (SC therapeutic injection) · 1 unit
# Per-dose reimbursement (Q2 2026)
Total: 560 units × $23.396 = $13,101.76 (administered + waste, both reimbursable)
# Per cycle (6 weekly doses)
Drug units: 6 × 560 = 3,360 units
Drug reimbursement: 3,360 × $23.396 = $78,610.56
Admin codes: 6 × 96372
Worked example — 70 kg patient, FDA-label vial-band rounding
# Per FDA-label table: 70 kg → 560 mg/week (no waste)
Vials: 2 × 280 mg = 560 mg
Per-dose claim: J9333 · 560 units · modifier JZ (no waste)
Per-dose drug reimbursement: 560 × $23.396 = $13,101.76
Per cycle (6 doses): 3,360 × $23.396 = $78,610.56
Vials: 2 × 280 mg = 560 mg
Per-dose claim: J9333 · 560 units · modifier JZ (no waste)
Per-dose drug reimbursement: 560 × $23.396 = $13,101.76
Per cycle (6 doses): 3,360 × $23.396 = $78,610.56
NDC reference FDA NDC Directory verified May 2026
| NDC (10-digit) | NDC (11-digit) | Strength | Package Size | Units / Vial |
|---|---|---|---|---|
50474-740-01 |
50474-0740-01 |
280 mg / 2 mL (140 mg/mL) | 1 single-dose vial per carton | 280 units (1 mg = 1 unit) |
50474-741-01 |
50474-0741-01 |
140 mg / 1 mL (140 mg/mL) | 1 single-dose vial per carton | 140 units |
Use carton-level 11-digit NDC, not vial-level. Payers expect the 11-digit NDC with the
N4 qualifier in the 24A shaded area of CMS-1500. Both the 280 mg and 140 mg presentations may appear
on the same claim when doses require a combined draw (e.g., 420 mg/week = 1 × 280 + 1 × 140).
Submit each NDC on a separate line tied to the corresponding mg.
Single-source product: UCB is the sole manufacturer of rozanolixizumab. There is no
biosimilar or therapeutic equivalent to Rystiggo as of May 2026. Vyvgart (efgartigimod, J9332) is a
different molecule, not a biosimilar.
Phase 2
Code the claim
SC therapeutic injection code; JW for waste; serology must be documented in chart.
Administration codes CPT verified May 2026
Rystiggo is a non-chemotherapy biologic SC infusion. SC therapeutic injection code applies.
| Code | Description | When to use |
|---|---|---|
96372 |
Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular | Primary code for Rystiggo. Bill once per weekly dose, six times per cycle. |
96369 / 96370 / 96371 |
SC infusion for therapy — initial 1 hour / each additional hour / additional pump set-up | Use ONLY when SC infusion exceeds 15 minutes and is administered via mechanical pump per CPT criteria. Most Rystiggo doses fit 96372 (single SC injection technique). |
96365 / 96366 |
IV therapeutic infusion (non-chemo) | NOT appropriate. Rystiggo is subcutaneous, not IV. |
96401 |
Chemotherapy administration, SC or IM, non-hormonal antineoplastic | NOT appropriate. Rystiggo is not antineoplastic. |
96372 vs 96369 distinction. Rystiggo is delivered via SC infusion pump over ~15 minutes
per dose. Most billers and payers treat each weekly dose as a single SC therapeutic injection (96372)
rather than an SC infusion series (96369–96371). Verify your MAC's local policy if you administer
via prolonged infusion technique; some MACs accept 96369 with documentation of pump duration >15 min.
Do not bill both 96372 and 96369 for the same dose.
Modifiers CMS verified May 2026
JW — expected on most strict-weight-dose claims
JW reports the discarded portion of a single-dose vial. Because Rystiggo is dosed by body weight (7 mg/kg) and supplied in 280 mg + 140 mg single-dose vials, partial-vial waste occurs on most strict 7 mg/kg doses (e.g., 70 kg → 490 mg target with 2 × 280 mg vials = 70 mg waste). Bill the administered units on the primary line and the wasted units on a separate line with the JW modifier. Both administered and discarded mg pay at ASP+6%.
JZ — when dose lands on vial multiple
JZ applies when no waste occurs — either the calculated 7 mg/kg lands exactly on a 140 mg multiple, or the practice follows the FDA-label weight-band rounding (280 / 420 / 560 / 840 mg) where no vial fraction is discarded. One of JZ or JW must be on every J9333 claim per CMS's July 2023 single-dose container policy (CR 12056).
Worked example — JW with 7 mg/kg in a 70 kg patient
# Calculated dose
7 mg/kg × 70 kg = 490 mg (target)
# Vials drawn
2 × 280 mg vial = 560 mg total
# Claim lines (per weekly dose)
Line 1: J9333 · 490 units (administered) · no modifier or JZ-only convention varies by MAC
Line 2: J9333 · 70 units · modifier JW (discarded)
Line 3: 96372 · 1 unit (SC therapeutic injection)
# NDC reporting (24A shaded area)
N4 + 50474-0740-01 + UN + 2 (for two 280 mg vials drawn)
7 mg/kg × 70 kg = 490 mg (target)
# Vials drawn
2 × 280 mg vial = 560 mg total
# Claim lines (per weekly dose)
Line 1: J9333 · 490 units (administered) · no modifier or JZ-only convention varies by MAC
Line 2: J9333 · 70 units · modifier JW (discarded)
Line 3: 96372 · 1 unit (SC therapeutic injection)
# NDC reporting (24A shaded area)
N4 + 50474-0740-01 + UN + 2 (for two 280 mg vials drawn)
Common error: Failing to bill the JW waste line on a strict 7 mg/kg dose. CMS audits
routinely catch this — the wasted drug is reimbursable but must be reported on a separate line.
Both administered and discarded units pay at ASP+6%.
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 SC injection. Routine pre-injection clinical assessment is bundled into 96372.
340B modifiers (JG, TB)
For 340B-acquired Rystiggo, follow your MAC's current 340B modifier policy. Hospital outpatient departments billing under OPPS are subject to specific 340B reporting requirements; office-based 340B reporting varies by MAC.
ICD-10-CM by indication FY2026 verified May 2026
Generalized myasthenia gravis only. Antibody status is documented in chart and PA but does not change the ICD-10 family.
| ICD-10 | Description | When to use |
|---|---|---|
G70.00 |
Myasthenia gravis without (acute) exacerbation | Primary code for stable cyclic Rystiggo dosing in clinic-confirmed gMG without active crisis |
G70.01 |
Myasthenia gravis with (acute) exacerbation | When chart documents MGFA Class III–V or rescue cycle initiated for symptom flare; supports medical-necessity narrative for re-cycle |
G70.2 / G70.3 / G70.8 / G70.9 |
Congenital and developmental myasthenia / Other / NOS | Not labeled. Off-label use; expect denial without strong narrative. |
Antibody status: chart documentation, not ICD-10. Both AChR-positive and MuSK-positive
gMG bill under G70.00 or G70.01. Anti-AChR or anti-MuSK serology results must be in the medical record
and PA submission (lab name, date, value, reference range), but ICD-10 does not distinguish. Seronegative
gMG is NOT a Rystiggo indication regardless of which G70.x code is selected.
Site of care & place of service Verified May 2026
Rystiggo is typically administered in neurology offices, ambulatory infusion centers, and hospital outpatient departments. The ~15-minute SC infusion fits cleanly into office and AIC slots, and the no-REMS / no-IV profile makes it suitable for stable patients to transition to home administration through a certified home infusion vendor after the first one or two cycles.
| Setting | POS | Claim form | Payer steering |
|---|---|---|---|
| Neurology office | 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 | Allowed initial cycles; disfavored thereafter |
| Hospital outpatient (off-campus PBD) | 19 | UB-04 / 837I | Disfavored |
| Patient home (stable patients) | 12 | CMS-1500 / 837P + home infusion S-codes | Acceptable after initial supervised cycles; coordinate with certified home infusion vendor |
Home infusion is plausible after stability. Because Rystiggo has no REMS, no boxed
warning, and a 15-minute SC dose, payers increasingly approve home administration for patients who
have tolerated 1–2 cycles in a supervised setting. Pair with S9329 (home infusion per diem) and
99601/99602 (home infusion administration) per vendor billing protocol. Verify the patient's plan
covers home infusion as a benefit before transitioning.
Claim form field mapping UCBcares Patient Support 2026
From UCBcares HCP coding & coverage materials (rystiggohcp.com).
| Information | CMS-1500 box | Notes |
|---|---|---|
| NPI | 17b | Rendering provider (neurologist or supervising MD) |
| NDC qualifier + 11-digit NDC + UoM + qty | 24A shaded area | N4 + 50474-0740-01 + UN + vials drawn (e.g., 2 for two 280 mg vials) |
| HCPCS J9333 + JW (waste line) | 24D (waste line) | Wasted mg when strict 7 mg/kg results in partial-vial discard |
| HCPCS J9333 (administered line) | 24D (drug line) | Administered mg; this is the larger line |
| Drug units | 24G | Actual mg administered (e.g., 490 for 7 mg/kg × 70 kg) |
| CPT 96372 (admin line) | 24D (admin line) | SC therapeutic injection, 1 unit per weekly dose |
| ICD-10 | 21 | G70.00 (stable) or G70.01 (exacerbation) |
| PA number | 23 | Required by all major commercial payers and Medicare Advantage |
Multi-vial NDC reporting: When a single dose draws from both 280 mg and 140 mg
presentations (e.g., 420 mg/week from 1 × 280 + 1 × 140), submit each NDC on a separate
line keyed to the corresponding mg portion. Payer adjudication systems map NDC to dispensing-unit
cost for AWP-based rebates.
Phase 3
Get paid
PA + antibody serology documentation + prior immunosuppressant trial are the gating items.
Payer policy snapshot Reviewed May 2026
All major payers require PA. Anti-AChR or anti-MuSK antibody documentation is universal. Step through prior immunosuppressant is common.
| Payer | PA? | Clinical criteria | Step therapy |
|---|---|---|---|
| UnitedHealthcare Med Benefit Drug Policy — Rystiggo |
Yes | Adult, generalized MG (not ocular-only), documented anti-AChR OR anti-MuSK antibody positivity, baseline MG-ADL or QMG score | Trial and failure / intolerance of pyridostigmine + at least one immunosuppressant (corticosteroid, azathioprine, mycophenolate, or comparable) |
| Aetna CPB Rystiggo (rozanolixizumab) |
Yes | Adult gMG, AChR+ or MuSK+ serology, prescribed by neurologist, baseline severity score documented | Inadequate response to or intolerance of one or more conventional immunosuppressants |
| Cigna / Express Scripts Coverage Policy 2104 |
Yes | Adult gMG, AChR+ or MuSK+, neurologist prescriber | Step through pyridostigmine + corticosteroid + immunosuppressant before FcRn class |
| BCBS plans Vary by plan |
Yes | Generally aligned with FDA label + MGFA / AAN guidance | Plan-specific; most require prior steroid + steroid-sparing immunosuppressant trial |
| Medicare (Part B) MAC LCDs (no NCD) |
No prior auth at MAC level; coverage by indication | FDA-approved indication; MAC-specific local coverage articles | None at Medicare; coverage applies for on-label gMG with appropriate documentation |
Re-treatment cycle documentation
Most commercial payers require chart documentation supporting clinical need for each new cycle — typically a MG-ADL or QMG score showing return of symptoms above pre-cycle baseline, or neurologist attestation that the patient is approaching the lower bound of the between-cycle response window. Minimum re-cycle interval per FDA label is 63 days from prior cycle start; some payers extend this to 9–13 weeks for utilization management. Document the trigger (symptom return, MG-ADL change, QMG change) in the chart at every re-cycle request.
MGFA / AAN guidance support
The Myasthenia Gravis Foundation of America (MGFA) International Consensus Guidance for the Management of Myasthenia Gravis (2020 update) supports FcRn inhibitors as targeted therapy for refractory gMG after inadequate response to conventional immunosuppression. AAN Quality Measurement and Reporting Subcommittee guidance similarly supports targeted biologics in moderate-to-severe gMG with documented autoantibody positivity.
Medicare reimbursement CMS Q2 2026 (live)
Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.
Q2 2026 payment snapshot — J9333
Effective April 1 – June 30, 2026 · Based on Q4 2025 ASP submissions
ASP + 6%
$23.396
per mg / per unit
490 mg dose (70 kg)
$11,464.04
7 mg/kg × 70 kg
6-week cycle (490 mg × 6)
$68,784.24
drug only, pre-sequestration
Wasted drug is reimbursable. Bill the JW line for the discarded portion — both
administered and discarded units pay at ASP+6%. For a strict 7 mg/kg dose in a 70 kg patient (490 mg
administered + 70 mg waste from 2 × 280 mg vials), the per-dose drug reimbursement is
560 × $23.396 = $13,101.76 before sequestration.
Sequestration: Approximately 2% reduction applies to actual paid amount, bringing
effective reimbursement to roughly ASP + 4.3% rather than ASP + 6%.
Coverage
No NCD specific to rozanolixizumab. Coverage falls under MAC LCDs for Part B-administered biologics. All MACs cover J9333 for FDA-approved on-label gMG with appropriate ICD-10 (G70.0x) and clinical documentation. Antibody serology results are expected in the medical record but are not a Medicare PA gate in the way they are at commercial payers.
Code history
- J9333 — permanent code "Injection, rozanolixizumab-noli, 1 mg" effective January 1, 2024.
- Pre-permanent-code period (July 2023 – December 2023) billed under transitional Q-codes or unclassified J3590; transition this to J9333 for retrospective claim audits.
- Q2 2026 ASP per CMS Part B file: $23.396/mg.
ASP trajectory
J9333 per-mg ASP+6% has drifted up modestly across CY2025 into 2026 (low-single-digit percent change per quarter); the current Q2 2026 figure ($23.396/mg) is the load-bearing number for live coverage estimates and is bound to the CareCost ASP layer. Historical per-quarter ASPs are available from the CMS Part B Drug ASP Pricing File archives.
Patient assistance — UCBcares Patient Support UCB verified May 2026
- UCBcares Patient Support: 1-844-599-2273 (1-844-599-CARE) / rystiggo.com — benefits investigation, prior authorization assistance, appeals support, nurse navigator program
- UCB Rystiggo Copay Program: commercial copay support; eligible commercially-insured patients may pay as little as $0 per dose with annual program maximum (excludes Medicare, Medicaid, TRICARE, VA, and other federal program patients)
- UCB Patient Assistance Program (PAP): free drug for uninsured / underinsured patients meeting income requirements; administered by UCBcares
- Foundations (Medicare patients): verify open neuromuscular / myasthenia gravis funds at:
- PAN Foundation — panfoundation.org / 1-866-316-7263
- HealthWell Foundation — healthwellfoundation.org / 1-800-675-8416
- Patient Advocate Foundation Co-Pay Relief — copays.org / 1-866-512-3861
- Myasthenia Gravis Foundation of America (MGFA) Patient Assistance — myasthenia.org / 1-800-541-5454
- Bridge / quick-start program: UCBcares offers a short-term bridge supply for patients with delayed PA approvals; enroll via the patient support center
Need to model what a specific patient will actually pay after copay assistance, deductible, coinsurance,
and OOP max? Run a CareCost Estimate — J9333 pre-loaded.
Phase 4
Fix problems
Missing antibody serology and missing immunosuppressant step are the top two denials.
Common denials & how to fix them
| Rank | Denial reason | Common cause | Fix |
|---|---|---|---|
| #1 | Anti-AChR / anti-MuSK antibody documentation missing or insufficient | PA submitted without lab report or with seronegative-only result; serology pending at time of PA | Submit the lab report (lab name, draw date, antibody value with reference range) for either anti-AChR or anti-MuSK. Both serotypes are covered under Rystiggo; resubmit MuSK-positive results explicitly when initial denial was framed as "AChR-only" coverage. Seronegative gMG is not coverable — appeal with serology repeat or alternative diagnosis. |
| #2 | Prior immunosuppressant trial not documented | PA missing step-therapy history (pyridostigmine, corticosteroid, azathioprine, mycophenolate, etc.) | Submit chart notes documenting prior agent(s), duration, dose, response, and reason for discontinuation (inadequate response, intolerance, contraindication). Most payers require at least one steroid-sparing immunosuppressant trial. |
| #3 | Re-treatment cycle justification missing | Continuation PA submitted without evidence of symptom return or score change | Submit MG-ADL or QMG score from current visit showing return toward pre-cycle baseline. Document the ≥ 63-day interval from previous cycle start. Include neurologist attestation that cycle re-initiation is clinically indicated. |
| #4 | Wrong CPT admin code | 96365 (IV infusion) or 96401 (chemo SC) billed in place of 96372 | Resubmit with 96372 (SC therapeutic injection). Rystiggo is non-chemo SC; chemo admin codes (96401) and IV codes (96365) are inappropriate. |
| #5 | JW waste line missing | Wasted units not reported on a strict 7 mg/kg dose | Add JW line for discarded units. Both administered and discarded units pay at ASP+6%. |
| #6 | Wrong HCPCS (J3590 / J9332) | Pre-permanent-code claim under unclassified J3590, or confused with Vyvgart J9332 | Resubmit with J9333 (permanent eff. 1/1/2024). Verify product administered: rozanolixizumab (J9333, UCB) vs efgartigimod (J9332, argenx). Different molecules. |
| #7 | Site of care (HOPD) on commercial plan | HOPD administration with active site-of-care UM | Move to office (POS 11), AIC (POS 49), or home (POS 12) for subsequent cycles. Submit medical-necessity letter if HOPD required (e.g., first dose monitoring). |
| #8 | Wrong NDC format (vial-level instead of carton) | 10-digit vial NDC submitted instead of 11-digit carton NDC with N4 qualifier | Use 11-digit carton NDC (50474-0740-01) with N4 qualifier in 24A shaded area. |
| #9 | Off-label diagnosis (seronegative gMG, congenital MG, ocular-only MG) | ICD-10 G70.0x submitted but chart documents seronegative or non-generalized disease | Rystiggo not approved for these populations. If the patient is truly AChR+ or MuSK+ generalized MG, correct the chart and resubmit; otherwise discontinue PA and consider alternative therapy. |
Frequently asked questions
What is the HCPCS code for Rystiggo?
Rystiggo (rozanolixizumab-noli) is billed under HCPCS J9333 — "Injection,
rozanolixizumab-noli, 1 mg." Each milligram equals one billable unit. A typical 7 mg/kg SC dose in a
70 kg patient is 490 mg = 490 units. The permanent code became effective January 1,
2024; earlier claims used a transitional code or unclassified J3590.
How is Rystiggo dosed?
7 mg/kg subcutaneously once weekly for 6 weeks per treatment cycle. Cycles are repeated based on clinical response, no sooner than day 63 from the start of the prior cycle. Per the FDA label dosing table, the calculated mg dose may be rounded to vial-multiple bands (280 / 420 / 560 / 840 mg); verify your facility protocol. Each weekly dose is given as a ~15-minute SC infusion.
Rystiggo vs Vyvgart (efgartigimod, J9332) — both FcRn inhibitors?
Yes — both target FcRn and reduce circulating IgG by ~60–70% per cycle. Key differences: Rystiggo (rozanolixizumab, IgG4 mAb) is approved for AChR+ AND MuSK+ gMG and is SC-only at 7 mg/kg weekly × 6. Vyvgart IV and Vyvgart Hytrulo SC (efgartigimod, IgG1 Fc fragment) are approved for AChR+ only at 10 mg/kg IV weekly × 4 (IV) or fixed 1,008 mg SC weekly × 4 (Hytrulo). Vyvgart Hytrulo also has a CIDP indication; Rystiggo does not. See the FcRn class comparison section.
Rystiggo vs Soliris (J1299) / Ultomiris (J1303) for gMG?
Different mechanism, different antibody population, different setting. Soliris (eculizumab) and Ultomiris (ravulizumab) are C5 complement inhibitors approved for AChR-positive gMG only, given as continuous IV therapy (Soliris q2wk; Ultomiris q8wk) with mandatory Alexion REMS for meningococcal infection risk. Rystiggo is an FcRn inhibitor approved for both AChR+ and MuSK+ gMG, given as cyclic SC therapy (6 weekly doses per cycle), without REMS. Many neurologists trial FcRn (Rystiggo or Vyvgart) before escalating to complement inhibitors in refractory AChR+ disease.
Does Rystiggo cover MuSK-positive gMG?
Yes — Rystiggo is the first and only FDA-approved targeted therapy specifically labeled for MuSK-positive gMG. The MuSK-positive population (roughly 5–8% of all gMG patients) was historically difficult to treat because complement inhibitors (Soliris, Ultomiris) are AChR-only and Vyvgart (the other FcRn agent) is also AChR-only. Document MuSK antibody positivity explicitly in the PA submission — some payers default to AChR-only review and need a corrective note that MuSK+ is also a labeled indication for Rystiggo specifically.
When can a re-treatment cycle be billed?
Per FDA label, a new cycle may begin no sooner than 63 days from the start of the prior cycle. Clinical re-treatment timing is based on the neurologist's assessment of symptom return — MG-ADL or QMG score trending back toward pre-cycle baseline. Some commercial payers extend the minimum re-cycle interval to 9–13 weeks for utilization management; document the clinical trigger (symptom return, score change) at every continuation PA.
Is anti-AChR or anti-MuSK testing required before starting Rystiggo?
Yes — FDA label restricts use to adults with anti-AChR OR anti-MuSK antibody positivity, and every major commercial payer requires the lab report in the PA packet. Acceptable serology includes radioimmunoprecipitation (RIPA), cell-based assay (CBA), or fluorescence immunoprecipitation assay for AChR and anti-MuSK ELISA or CBA for MuSK. Document lab name, draw date, value, and reference range. Seronegative gMG (negative for both AChR and MuSK) is not a labeled indication.
Is Rystiggo approved in pediatric patients?
No. Rystiggo is FDA-approved for adults only (18 years and older). Safety and effectiveness in pediatric patients have not been established. Pediatric gMG patients should be managed per pediatric neurology guidance with FDA-approved pediatric agents and supportive care; off-label Rystiggo use in pediatrics will be denied.
What is an FcRn inhibitor and how does it work?
The neonatal Fc receptor (FcRn) is a salvage receptor in vascular endothelium and other tissues that binds circulating IgG and returns it to the bloodstream, dramatically extending IgG half-life (~21 days for endogenous IgG vs ~1–3 days for other plasma proteins). FcRn inhibitors competitively block FcRn-IgG binding, accelerating IgG catabolism and lowering circulating IgG (including pathogenic autoantibodies) by ~60–70% per treatment cycle. In gMG, this transiently reduces anti-AChR or anti-MuSK autoantibody levels and improves neuromuscular transmission. The effect is reversible; IgG levels recover between cycles, which is why dosing is cyclic rather than continuous.
Reference
Sources & methodology
Every claim on this page is sourced. Methodology and review history below.
Source documents
- FDA — RYSTIGGO (rozanolixizumab-noli) prescribing information (BLA 761286, approved June 26, 2023)
- DailyMed — RYSTIGGO (rozanolixizumab-noli) current prescribing information
- Bril V, et al. — MycarinG pivotal trial of rozanolixizumab in generalized myasthenia gravis (Lancet Neurology, 2023)
- UCB — Rystiggo HCP coding & coverage (rystiggohcp.com)
- CMS — Medicare Part B Drug ASP Pricing File
- SEER CanMED — HCPCS J9333 reference
- MGFA — International Consensus Guidance for Management of Myasthenia Gravis (2020 update)
- UnitedHealthcare — Medical Benefit Drug Policies (Rystiggo)
- Aetna Clinical Policy Bulletins — Rozanolixizumab (Rystiggo)
- CMS HCPCS Level II Quarterly Updates
- FDA National Drug Code Directory
- CMS — JW/JZ modifier policy (CR 12056, eff. July 2023)
About this page
We maintain this page as a living reference. Medicare ASP pricing is bound to our underlying CareCost data layer and refreshes automatically when CMS publishes new quarterly files. Coding and policy content is reviewed at least quarterly and updated whenever a source document changes.
Found an error? Email hello@carecostestimate.com.
Refresh cadence
| Element | Cadence | How it's refreshed |
|---|---|---|
| Medicare ASP pricing | Quarterly | Auto-bound to CareCost ASP layer; updates on CMS file release. |
| Payer policies (UHC, Aetna, BCBS, Cigna) | Semi-annual | Manual review against published payer policy documents. |
| HCPCS / CPT / modifier rules | Annual | Reviewed against CMS HCPCS quarterly files and AMA CPT releases. |
| NDC, dosing, FDA label | Event-driven | Tied to manufacturer document version + FDA label revision date. |
Reviewer
Pending SME review. This page is staff-authored from primary sources (FDA, CMS, UCB,
MGFA, and payer documents — all linked above). Editorial review in progress. Until that review
is complete, treat this as a draft reference and verify each cited source for high-stakes claims.
Change log
- — Initial publication. ASP data: Q2 2026 ($23.396/mg). Manufacturer source: UCBcares Patient Support 2026. Coverage: gMG in adults AChR+ or MuSK+. FcRn class comparison vs Vyvgart (J9332). Cross-links to Soliris (J1299) and Ultomiris (J1303) for gMG class context.
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 list and dosing are verified against the current FDA label revision. We do not paraphrase from billing-software vendor blogs.