Bizengri (J9382) Billing & Coding Guide | Zenocutuzumab

Phase 1 Identify what you're billing Confirm NRG1 fusion status from a validated RNA-based NGS report before any other coding. No NRG1 fusion = no coverage.

Dosing & unit math FDA label verified May 2026

From the FDA prescribing information for Bizengri (zenocutuzumab-zbco), December 2024 accelerated approval.

Adult dosing — both approved indications

750 mg IV every 2 weeks (q14d), flat dose (not weight-based; not BSA-based)
Same dose for both NRG1+ NSCLC and NRG1+ pancreatic adenocarcinoma
Continue until disease progression or unacceptable toxicity
First infusion: 4 hours. Observe during and after first infusion for infusion-related reactions.
Subsequent infusions: 2 hours if first dose tolerated
If a planned dose is missed, administer the next dose as soon as possible and resume the q14d schedule

Preparation

Each 375 mg / 18.75 mL single-dose vial is a clear, colorless to slightly yellowish solution at 20 mg/mL.
No reconstitution required — ready-to-dilute liquid formulation.
For a 750 mg dose, withdraw 37.5 mL total (from 2 vials × 18.75 mL).
Dilute in 0.9% Sodium Chloride Injection or 5% Dextrose Injection infusion bag per label instructions.
Do not shake. Mix by gentle inversion. Protect from light during storage.
Administer through a dedicated IV line using a 0.2 or 0.22 micron in-line, low-protein-binding filter per current PI.

Premedication for infusion-related reactions

First dose (and as needed for subsequent): antihistamine (e.g., diphenhydramine), antipyretic (e.g., acetaminophen), and corticosteroid (e.g., dexamethasone) per institutional protocol
If a Grade 1 or 2 infusion-related reaction occurs, premedicate before all subsequent infusions; consider extending infusion time
For Grade 3 reaction: hold, treat, restart at slower rate after recovery; for Grade 4: permanently discontinue

Worked example — standard 750 mg flat dose, full year

# Per-dose math (flat — same for every patient, every cycle) Dose: 750 mg flat (not weight-based) Vials drawn: 750 / 375 = exactly 2 vials (750 mg total drawn) Drug billed: 750 mg = 750 units (J9382 + JZ) Drug wasted: 0 mg = 0 units (no JW line needed) Admin: 96413 (first hr) + 96415 \times 3 (3 addl hrs, first dose only); 96413 + 96415 \times 1 subsequent # Per cycle (one infusion every 14 days) Doses per cycle: 1 infusion q14d Drug units billed per cycle: 750 (zero waste) # Year-1 (~26 cycles) Total infusions: 26 (q14d \times 52 wk = 26 doses/year) Total drug units administered: ~19,500 units Total drug cost (Q2 2026 ASP+6%): ~$654,557 before sequestration After ~2% sequestration: ~$641,466 actual paid

Why JZ (no waste) is the rule for Bizengri: The 375 mg vial size divides evenly into the flat 750 mg dose (2 vials × 375 mg = 750 mg exactly). No partial-vial waste → JZ applies on every claim. JW is only needed when toxicity-driven dose reductions cause partial vials to be drawn but not fully administered — verify your pharmacy's actual draw versus administered mg before adding a JW line.

Dose-reduction scenarios: For Grade 3+ toxicity-related dose reductions, the label permits reducing to 600 mg q14d. A 600 mg dose still requires 2 vials drawn (750 mg drawn) → 600 mg JZ + 150 mg JW on separate lines. Document the toxicity-driven reduction in chart and on the claim.

NDC reference FDA NDC Directory verified May 2026

NDC	Strength	Package Size	Units/Vial
`83077-100-01` / `83077-0100-01`	375 mg / 18.75 mL (20 mg/mL)	Single-dose vial — 1 vial per carton	375 units (1 mg = 1 unit)
`83077-100-02` / `83077-0100-02`	375 mg / 18.75 mL (20 mg/mL)	2-vial carton (sufficient for one 750 mg dose)	750 units per carton

Verify 11-digit NDC format on current DailyMed label. Submit the 11-digit carton NDC with the N4 qualifier on the claim line. Vial-level NDC will trigger denial. For a standard 750 mg dose, two cartons are dispensed — bill NDC quantity reflecting total mL drawn from vials (37.5 mL for 2 full vials) under unit-of-measure ML.

NDC unit-of-measure reminder: Each 375 mg vial contains 18.75 mL at 20 mg/mL (ready-to-use solution — no reconstitution). NDC quantity on the claim should reflect total mL drawn from vials (not mg, not units). For the standard 750 mg dose, 2 vials × 18.75 mL = 37.5 mL drawn and administered.

NRG1 fusion testing — the universal coverage gate NCCN / payer policies verified May 2026

Bizengri coverage is gated entirely on documented NRG1 (neuregulin-1) gene fusion identification. This is the single highest-yield piece of documentation for PA approval and the #1 denial driver when missing.

NRG1 fusions are rare driver mutations: present in roughly 0.2–0.3% of NSCLC (enriched in mucinous adenocarcinoma and never-smokers) and 0.5–1.5% of pancreatic adenocarcinomas (enriched in KRAS wild-type pancreatic cancer). Detection is technically challenging: NRG1 spans >1 Mb of genomic DNA with very large introns, so DNA-based NGS panels frequently miss NRG1 fusions. RNA-based NGS is the recommended detection method.

Validated detection panels

FoundationOne CDx (DNA + RNA hybrid; detects most clinically relevant NRG1 fusion partners)
FoundationOne Liquid CDx (ctDNA — lower sensitivity for NRG1 specifically)
Tempus xR (RNA-based; high sensitivity for NRG1 fusion partners)
Caris MI Tumor Seek (whole exome + transcriptome; broad fusion detection)
Memorial Sloan Kettering MSK-Fusion (RNA-based, validated)
RNA-based NGS via local academic pathology labs (acceptable if methodology documented)

Common NRG1 fusion partners (document the specific partner in chart)

CD74-NRG1 — most common in NSCLC (mucinous adenocarcinoma); historical "signature" partner
ATP1B1-NRG1, SLC3A2-NRG1, SDC4-NRG1 — recurrent in NSCLC + pancreatic
RBPMS-NRG1, WRN-NRG1, POMK-NRG1 — recurrent in pancreatic
Over 30 unique 5' partner genes reported; payers generally accept any documented in-frame fusion involving NRG1 EGF-like domain

Documentation for PA submission: include the full molecular pathology report showing (1) NRG1 fusion called, (2) specific 5' partner identified, (3) testing methodology (RNA-based NGS preferred; specify panel name and lab), (4) report date and ordering physician. Most payers will not approve based on "NRG1 fusion positive" alone without partner and methodology.

DNA-only NGS without NRG1 detected ≠ NRG1 fusion-negative. If a patient was tested only with a DNA-based panel and NRG1 was not reported, consider repeat testing with an RNA-based panel before ruling out NRG1 fusion — particularly in mucinous NSCLC adenocarcinoma and KRAS wild-type pancreatic adenocarcinoma where NRG1 fusion prevalence is enriched.

Phase 2 Code the claim Chemo admin codes apply. JZ is the rule for the 750 mg standard dose (zero waste from 2 × 375 mg vials).

Administration codes CPT verified May 2026

Bizengri is a therapeutic monoclonal antibody for cancer treatment — chemotherapy administration codes are correct per AMA classification.

Code	Description	When to use
`96413`	Chemotherapy administration, IV infusion technique; up to 1 hour, single or initial substance/drug	Primary code for every Bizengri infusion. Covers the first 60 minutes of the infusion.
`96415`	Chemotherapy administration, IV infusion; each additional hour	Required for both first and subsequent doses given Bizengri's long infusion times. First dose (4 hr) = 96413 + 96415 × 3. Subsequent dose (2 hr) = 96413 + 96415 × 1.
`96365` / `96366`	Therapeutic IV infusion (non-chemo)	NOT appropriate. Bizengri is an antineoplastic agent and chemotherapy administration codes apply per AMA classification.
`96360` / `96361`	Hydration IV	Bill separately if IV hydration administered alongside infusion. Use modifier 59 / X-modifier as appropriate.

Infusion-time math: First-dose 4-hour infusion bills 96413 × 1 + 96415 × 3. Subsequent 2-hour infusions bill 96413 × 1 + 96415 × 1. Document actual infusion start/stop times in the medical record — CMS audits look for chair-time documentation matching billed units. If reactions slow the infusion, the actual hours billed may exceed plan; document the clinical event.

96415 unit cap awareness: Many MACs limit 96415 to a maximum of 8 units per encounter. Bizengri's 3-hour and 1-hour additional infusion times are well within limits, but combination with other long infusions on the same day can hit the cap — verify same-day chemo regimens.

Modifiers CMS verified May 2026

JZ — the rule on most Bizengri claims

Effective July 1, 2023, CMS requires either JZ (no waste) or JW (drug discarded from a single-dose container) on every J9382 claim. Because Bizengri is dosed as a flat 750 mg that divides evenly into 2 × 375 mg vials, the standard dose produces zero waste — JZ applies on virtually every claim.

Standard 750 mg dose: 2 vials × 375 mg = 750 mg drawn = 750 mg administered → J9382-JZ × 750 units; no JW line.
Dose-reduced 600 mg dose (toxicity-related): 2 vials × 375 mg = 750 mg drawn; 600 mg administered + 150 mg wasted → J9382-JZ × 600 units AND J9382-JW × 150 units on a separate claim line.
Both lines (when applicable) must reconcile against total mg drawn from vials.

Worked example — standard 750 mg dose

# Vials and waste (standard 750 mg) Vials drawn: 2 \times 375 mg = 750 mg total Administered: 750 mg = 750 units \to J9382-JZ Discarded: 0 mg = 0 units \to no JW line # Claim lines (first dose) Line 1: J9382-JZ \times 750 units Line 2: 96413 (admin, first hr) Line 3: 96415 \times 3 (3 addl hrs, first dose 4-hr infusion) # Claim lines (subsequent dose) Line 1: J9382-JZ \times 750 units Line 2: 96413 (admin, first hr) Line 3: 96415 \times 1 (1 addl hr, 2-hr infusion)

Worked example — dose-reduced 600 mg (Grade 3 toxicity recovery)

# Vials and waste (dose-reduced 600 mg) Vials drawn: 2 \times 375 mg = 750 mg total (still 2 vials — can't draw partial) Administered: 600 mg = 600 units \to J9382-JZ Discarded: 150 mg = 150 units \to J9382-JW (separate line) # Claim lines Line 1: J9382-JZ \times 600 units Line 2: J9382-JW \times 150 units — document toxicity-driven reduction Line 3: 96413 (admin, first hr) Line 4: 96415 \times 1 (1 addl hr, 2-hr infusion)

Common error: Adding a JW line on the standard 750 mg dose where no waste actually occurred — the 2-vial draw is exactly 750 mg. CMS audits routinely catch fabricated waste; only report JW units that reflect actual discarded drug from a single-dose container.

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., LVEF assessment review, toxicity-driven dose modification decision, infusion-reaction management). Routine pre-infusion clinical assessment is bundled.

340B modifiers (JG, TB)

For 340B-acquired Bizengri, follow your MAC's current 340B modifier policy. As of May 2026, JG (340B-acquired, normal payment) and TB (340B-acquired, informational) policy varies by region; verify with your MAC.

ICD-10-CM by indication FY2026 verified May 2026

Use the most specific code supported by encounter documentation; ICD-10 alone is never sufficient for PA approval — the NRG1 fusion molecular pathology report must accompany the submission.

Indication	Primary ICD-10	Required supporting documentation
Advanced unresectable / metastatic NRG1+ NSCLC	`C34.x1` (right lung) / `C34.x2` (left lung) by lobe	NRG1 fusion molecular pathology report (RNA-based NGS preferred) with specific 5' partner; histology (often mucinous adenocarcinoma); prior systemic therapy history; `C79.x` for metastatic sites (e.g., `C79.51` bone, `C79.31` brain, `C78.7` liver)
Advanced unresectable / metastatic NRG1+ pancreatic adenocarcinoma	`C25.0` – `C25.9` by anatomic location	NRG1 fusion molecular pathology report (RNA-based NGS preferred) with specific 5' partner; histology (adenocarcinoma); prior systemic therapy history; `C78.x` / `C79.x` for metastatic sites (e.g., `C78.7` liver, `C78.6` peritoneum, `C78.0x` lung)

Common NSCLC C34 codes

Code	Location
`C34.01 / C34.02`	Main bronchus (R/L)
`C34.11 / C34.12`	Upper lobe (R/L)
`C34.2`	Middle lobe (right)
`C34.31 / C34.32`	Lower lobe (R/L)
`C34.81 / C34.82`	Overlapping sites (R/L)
`C34.91 / C34.92`	Unspecified part (R/L)

Pancreatic adenocarcinoma C25 codes

Code	Location
`C25.0`	Head of pancreas (most common)
`C25.1`	Body of pancreas
`C25.2`	Tail of pancreas
`C25.3`	Pancreatic duct
`C25.4`	Endocrine pancreas (rare; not typical Bizengri context)
`C25.7`	Other parts of pancreas
`C25.8`	Overlapping sites of pancreas
`C25.9`	Pancreas, unspecified

Secondary metastatic site codes (add as appropriate)

Code	Site
`C78.0x`	Secondary malignant neoplasm of lung (R/L/unspec)
`C78.6`	Secondary malignant neoplasm of peritoneum and retroperitoneum
`C78.7`	Secondary malignant neoplasm of liver
`C79.31`	Secondary malignant neoplasm of brain
`C79.51`	Secondary malignant neoplasm of bone
`C77.x`	Secondary and unspecified malignant neoplasm of lymph nodes

Indication-specific PA criteria are universal. Every major payer requires (1) ICD-10 confirming NSCLC or pancreatic adenocarcinoma, (2) line-of-therapy documentation showing previously treated advanced/metastatic disease, (3) NRG1 fusion molecular pathology report with specific fusion partner and testing methodology. ICD-10 alone will result in denial.

Accelerated approval status: Both Bizengri indications are accelerated approvals (Dec 4, 2024) based on the eNRGy trial (NCT02912949) overall response rate and duration of response. Continued approval may be contingent on confirmatory trial results. Coverage is established across major payers as of May 2026, but verify current FDA label and your payer's medical policy for any post-marketing changes.

Site of care & place of service Verified May 2026

Bizengri's 4-hour first-dose infusion with active infusion-reaction monitoring requires a setting with reaction-management capability — typically a hospital outpatient infusion center, ambulatory infusion suite, or physician oncology office equipped for prolonged chemo-class infusions. Subsequent 2-hour infusions are more flexible and transition cleanly to physician office or freestanding infusion suites. Major commercial payers (UnitedHealthcare, Aetna, BCBS) run site-of-care UM steering specialty oncology drugs out of HOPD for subsequent cycles — document clinical rationale if HOPD continued past Cycle 1.

Setting	POS	Claim form	Payer steering
Physician oncology office	11	CMS-1500 / 837P	Preferred by commercial UM (Cycle 2+)
Ambulatory infusion suite (AIC) / freestanding infusion center	49	CMS-1500 / 837P	Preferred by commercial UM
Oncology ASC	24	CMS-1500 / 837P	Acceptable
Hospital outpatient (on-campus)	22	UB-04 / 837I	Acceptable Cycle 1 (first 4-hr infusion); disfavored Cycle 2+ by most commercial UM
Hospital outpatient (off-campus PBD)	19	UB-04 / 837I	Disfavored after first cycle by most commercial UM
Patient home	12	CMS-1500 (with home infusion)	Rare given infusion-reaction risk + LVEF monitoring requirements; clinic-based delivery preferred

First-dose recommendation: Schedule the first Bizengri dose in a setting with infusion-reaction management capability and a minimum 4-hour infusion window plus observation. Many practices use HOPD or AIC for Cycle 1 and transition to physician office (POS 11) for Cycle 2+ once tolerability is established. Document this clinical rationale in chart for any HOPD site-of-care UM appeal on subsequent cycles.

Claim form field mapping Merus Reimbursement Guide 2026

Standard 750 mg Bizengri claims have one J9382-JZ line (no JW unless dose-reduced). Account for 96413 + 96415 admin lines based on infusion duration.

Information	CMS-1500 box	Notes
NPI	17b	Rendering provider
NDC qualifier + 11-digit NDC + UoM + qty	24A shaded area	N4 + `83077-0100-01` + ML + total volume drawn (37.5 mL for 2 full vials)
HCPCS J9382 + JZ (administered units)	24D (drug line)	Units = administered mg (1 unit = 1 mg); standard 750 units for full dose
HCPCS J9382 + JW (wasted units)	24D (separate drug line, if applicable)	Only if toxicity-driven dose reduction caused partial-vial waste; e.g., 600 mg dose → 150 mg JW
Drug units	24G	Per line; ensure JZ (+ JW if applicable) sum to total mg drawn from vials
CPT 96413 (admin line)	24D (admin line)	First hour of infusion (every Bizengri encounter)
CPT 96415 (admin line)	24D (admin line)	Additional hours — first dose: × 3 (4-hr infusion); subsequent: × 1 (2-hr infusion)
ICD-10	21	Indication-specific (C34.x for NSCLC, C25.x for pancreatic); pair with metastatic-site C78.x / C79.x codes
PA number	23	Required by all major commercial payers; NRG1 fusion molecular pathology report must accompany PA submission

Phase 3 Get paid NRG1 fusion molecular pathology report attachment to PA is non-negotiable. LVEF baseline + monitoring is increasingly expected.

Payer policy snapshot Reviewed May 2026

All major payers require PA. Universal gate: documented NRG1 fusion from validated test (RNA-based NGS preferred). Aetna CPB 1076 and equivalent UHC/BCBS policies all hinge on the fusion report.

Payer	PA?	Documentation focus	Site-of-care UM
UnitedHealthcare Oncology Med Coverage Policy	Yes	NRG1 fusion molecular pathology report required (RNA-based NGS preferred); advanced/metastatic stage; previously treated (1+ prior line of systemic therapy); ICD-10 confirming NSCLC or pancreatic adenocarcinoma; baseline LVEF	Aggressive: site-of-care steering away from HOPD via Optum-managed program from Cycle 2 onward
Aetna CPB 1076 (Bizengri/zenocutuzumab) + Medical Drug policies	Yes	NRG1 fusion documentation by validated NGS panel (specifying methodology); aligned with NCCN compendium NRG1-fusion entry; previously treated advanced/metastatic disease; ECOG performance status documentation	Yes (separate Site-of-Care policy; HOPD steering after Cycle 1)
BCBS plans Vary by plan	Yes	Generally aligned with NCCN compendium NRG1-fusion entry + FDA label; NRG1 fusion molecular report required; some plans (Anthem, BCBS-MA) require baseline LVEF and pulmonary assessment documentation	Plan-specific; most have ICI/ADC/specialty-mAb site-of-care steering after first cycle
Medicare All MACs — LCDs + NCCN compendium	No (Part B medical benefit)	All MACs cover J9382 for FDA-approved indications with appropriate ICD-10 and NRG1 fusion documentation; NCCN compendium support present for both NSCLC and pancreatic NRG1-fusion settings	Limited; Medicare has no formal site-of-care UM

Step therapy

Bizengri is a later-line therapy by FDA label design (advanced unresectable/metastatic, previously treated). Step therapy is typically baked into the line-of-therapy documentation rather than enforced as a separate gate. Expect payers to require evidence of at least one prior line of systemic therapy for metastatic disease (chemotherapy and/or immunotherapy as appropriate to histology) before approving Bizengri. For NRG1+ NSCLC, prior platinum-based chemotherapy is typically expected. For NRG1+ pancreatic adenocarcinoma, prior gemcitabine-based or FOLFIRINOX-based chemotherapy is typically expected.

NCCN compendium support

NCCN added zenocutuzumab to its compendium for NRG1 fusion-positive NSCLC and NRG1 fusion-positive pancreatic adenocarcinoma following the December 2024 FDA approval. Both are Category 2A recommendations in the post-progression molecular-targeted setting for tumors harboring NRG1 fusions. Compendium support is the practical backbone for Medicare and commercial coverage acceptance.

Medicare reimbursement CMS Q2 2026 (live)

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

Q2 2026 payment snapshot — J9382

Effective April 1 – June 30, 2026 · Based on 4Q25 ASP submissions

ASP + 6%

$33.567

per mg (1 unit = 1 mg)

750 mg flat dose

$25,175.25

750 units × ASP+6% (pre-sequestration)

600 mg reduced dose

$20,140.20

600 units × ASP+6% (admin only; 150 mg JW pays additionally)

Annualized cost (standard 750 mg q14d): 1 dose per cycle × ~26 cycles per year = 26 infusions; ~$654,557/year drug cost at Medicare ASP+6% before sequestration. After ~2% sequestration: ~$641,466/year actual paid. There is no waste cost on standard dosing (zero JW). ASP is updated quarterly by CMS — next update: July 1, 2026 for Q3.

Coverage

No NCD specific to zenocutuzumab-zbco. Coverage falls under MAC LCDs for biologics + the generic drug-coverage framework. All MACs cover J9382 for FDA-approved on-label indications with appropriate ICD-10 and NRG1 fusion molecular pathology documentation. NCCN compendium support present for both indications.

Code history

Dec 4, 2024 – Jun 30, 2025 — Bizengri billed under unclassified J3490 / J9999 or transitional pass-through C9399 with NDC and dose documentation following the December 4, 2024 FDA accelerated approval
J9382 effective July 1, 2025 — permanent code "Injection, zenocutuzumab-zbco, 1 mg"; verify your MAC's exact crosswalk date for any claims that straddle the transitional period

Patient assistance — Bizengri Access Program (Merus) Merus verified May 2026

Bizengri Access Program (Merus): 1-833-MERUS-4U (1-833-637-8748) / bizengri.com/access — benefits investigation, prior authorization assistance, appeal support, copay program enrollment, and PAP referrals
Bizengri Copay Program (commercial copay): eligible commercially insured patients may pay reduced out-of-pocket per infusion through the manufacturer copay program; verify current annual maximum benefit and program rules at enrollment (excludes Medicare, Medicaid, federal program patients)
Merus Patient Assistance Program (PAP): free Bizengri for uninsured / underinsured patients meeting income eligibility criteria (typically based on household income relative to Federal Poverty Level — verify current threshold at enrollment); enrollment processed through the Bizengri Access Program
Foundations for Medicare patients: refer to PAN Foundation, HealthWell Foundation, CancerCare, and Good Days — verify open NSCLC and pancreatic cancer copay funds quarterly (oncology fund availability is highly volatile). NRG1+ pancreatic patients may also benefit from pancreatic-specific foundation funds such as the National Pancreas Foundation.
Web: bizengri.com (HCP/patient portal) / merus.nl (corporate)

Need to model what a specific patient will actually pay after copay assistance, deductible, coinsurance, and OOP max? Run a CareCost Estimate — J9382 pre-loaded.

Phase 4 Fix problems Missing NRG1 fusion documentation, cross-product confusion with Ziihera, and over-billed JW lines (where standard 750 mg dose has zero waste) are the recurring problems.

Common denials & how to fix them

Denial reason	Common cause	Fix
#1: NRG1 fusion documentation missing or insufficient	PA submitted without NRG1 fusion molecular pathology report attached; or report lacks specific 5' fusion partner; or test was DNA-only without RNA-based confirmation	Attach full molecular pathology report showing NRG1 fusion call, specific 5' partner (e.g., CD74-NRG1), testing methodology (RNA-based NGS preferred — FoundationOne CDx, Tempus xR, Caris MI Tumor Seek), report date, and ordering physician. If only DNA-based NGS was done with no NRG1 hit, consider repeat RNA-based testing before submitting.
Wrong HCPCS code submitted	Bizengri accidentally billed under C9302 (Ziihera/zanidatamab) or other HER2-directed code by cross-confusion	Resubmit with J9382. Verify HCPCS matches actual product dispensed (zenocutuzumab-zbco = J9382); document NDC `83077-0100-01` on claim line. Ziihera is C9302 transitional pass-through — not the same drug.
JW line submitted with no actual waste	Biller added JW out of habit on a standard 750 mg dose that draws exactly 2 vials = 750 mg with zero discard	Remove JW line. Standard 750 mg dose = 2 vials × 375 mg = 750 mg drawn = 750 mg administered = 0 mg wasted. Bill JZ only.
JZ + JW units don't reconcile to vials drawn	Math error on dose-reduced claims: JZ + JW units should equal vials drawn × 375 mg	Recompute: total mg drawn = vials × 375; administered mg = JZ units; (drawn mg − admin mg) = JW units. For 600 mg dose: 2 vials = 750 drawn, 600 JZ + 150 JW.
Wrong admin code (96365)	Therapeutic IV billed instead of chemo IV	Resubmit with 96413 (every dose) and 96415 (3 additional hr first dose; 1 additional hr subsequent). Bizengri is an antineoplastic mAb — chemo administration codes apply per AMA classification.
96415 unit miscount	96415 billed × 1 on first 4-hour infusion instead of × 3	Audit infusion start/stop documentation. First dose 4-hr infusion = 96413 + 96415 × 3. Subsequent 2-hr infusion = 96413 + 96415 × 1.
Wrong NDC format (vial vs carton)	Vial NDC submitted instead of 11-digit carton NDC	Use carton NDC: `83077-0100-01` with N4 qualifier in 24A shaded.
PA denial — sequence-of-therapy not documented	Previously treated status (1+ prior line of systemic therapy for advanced/metastatic disease) not documented	Submit complete clinical history including all prior lines of systemic therapy with dates and reason for discontinuation (progression vs toxicity). For NSCLC, document prior platinum-based regimen. For pancreatic, document prior gemcitabine-based or FOLFIRINOX-based regimen.
Site of care (HOPD)	HOPD administration after first cycle on commercial plan with site-of-care UM	Move to office (POS 11) or AIC (POS 49) for Cycle 2+. Submit medical necessity letter if HOPD required (e.g., active infusion-reaction history, LVEF monitoring required, hospital-coordinated care).
Confusion with Ziihera (zanidatamab) coverage criteria	Biller cited HER2+ biliary tract cancer criteria (which apply to Ziihera/C9302) instead of NRG1 fusion criteria (which apply to Bizengri/J9382)	Resubmit with NRG1 fusion documentation. Bizengri and Ziihera are two separate drugs with totally different molecular targets and indications — review NCCN compendium entries and FDA labels for each before resubmitting.
LVEF / cardiac assessment missing	Some commercial PA reviews request baseline LVEF (echocardiogram or MUGA) given HER2/HER3 mechanism	Submit baseline LVEF report (within 3 months of treatment start) and institutional cardiac monitoring protocol with appeal letter. Per label, LVEF assessment is recommended at baseline and every 3 months during therapy.

Frequently asked questions

What is the HCPCS code for Bizengri?

Bizengri (zenocutuzumab-zbco) is billed under HCPCS J9382 — "Injection, zenocutuzumab-zbco, 1 mg." One billable unit equals 1 mg, the standard mAb convention. J9382 became a permanent code effective July 1, 2025; pre-July 2025 doses billed under unclassified J3490 or C9399 transitional pass-through following the December 4, 2024 FDA accelerated approval. Verify your MAC's crosswalk if billing any claims that straddle the transitional period.

Is Bizengri the same as Ziihera?

No — these are two completely different drugs approved within weeks of each other in late 2024. Bizengri (zenocutuzumab-zbco) is a HER2/HER3 (ErbB2/ErbB3) bispecific antibody from Merus, billed under J9382, approved December 4, 2024 for NRG1 gene fusion-positive NSCLC and pancreatic adenocarcinoma. Ziihera (zanidatamab-hrii) is a HER2-targeted bispecific antibody from Jazz Pharmaceuticals, billed under C9302 (transitional pass-through), approved November 20, 2024 for HER2+ biliary tract cancer (BTC). Different mechanism, different target, different indication, different HCPCS. Cross-confusion between these two drugs is one of the highest-risk biller errors in 2026.

What is the billing unit for J9382?

1 unit = 1 mg, per the CMS HCPCS descriptor "Injection, zenocutuzumab-zbco, 1 mg." Total mg administered = units billed. Bizengri is dosed as a flat 750 mg every 2 weeks — not weight-based — so the standard dose is always 750 units. Each 375 mg single-dose vial = 375 units. Standard 750 mg dose requires exactly 2 vials = 750 mg drawn, zero waste, JZ only.

What dose of Bizengri is given and how often?

Bizengri is dosed as 750 mg IV every 2 weeks (q14d), flat dose — not weight-based or BSA-based. The first infusion is administered over 4 hours; subsequent infusions over 2 hours if the first is well-tolerated. Treatment continues until disease progression or unacceptable toxicity. Both approved indications (NRG1+ NSCLC and NRG1+ pancreatic adenocarcinoma) share the same flat 750 mg q14d regimen.

What administration CPT do I use for Bizengri?

CPT 96413 for the first hour of every Bizengri infusion. For the first dose (4-hour infusion) bill 96413 × 1 + 96415 × 3 (three additional hours). For subsequent 2-hour infusions bill 96413 × 1 + 96415 × 1 (one additional hour). Bizengri is a true antineoplastic monoclonal antibody — chemotherapy administration codes are appropriate per AMA classification. Do NOT use 96365 (therapeutic IV).

What's the modifier for Bizengri? Do I need JW?

JZ on most claims; JW is rare. The standard 750 mg flat dose requires exactly 2 × 375 mg vials = 750 mg drawn with zero waste, so JZ (no waste from a single-dose container) applies. JW is only required for partial doses given for toxicity-related dose reductions when waste actually occurs (e.g., reducing to 600 mg from 2 vials = 150 mg JW + 600 mg JZ). Effective July 1, 2023, CMS requires either JZ or JW on every J9382 claim — one or the other, never neither, never both on the same line.

What is the Medicare reimbursement for J9382?

For Q2 2026, the Medicare Part B payment limit for J9382 is $33.567 per mg at ASP + 6%. A standard 750 mg flat dose = 750 units × $33.567 = $25,175.25 per dose. Cycles are every 14 days; an annualized course (~26 cycles per year) is roughly ~$654,500/year in drug cost (ASP + 6%) before sequestration. After ~2% sequestration: approximately $641,400/year actual paid.

Why is NRG1 fusion documentation the most common denial?

Bizengri is the first and only FDA-approved therapy specifically for NRG1 (neuregulin-1) gene fusion-positive solid tumors — a rare driver mutation found in <1% of NSCLC and 0.5–1.5% of pancreatic adenocarcinomas. Payer PA criteria universally require documented NRG1 fusion identified by a validated test (typically RNA-based NGS panel; DNA-based NGS often misses NRG1 fusions due to large intronic regions). Reports must show the specific fusion partner (e.g., CD74-NRG1, ATP1B1-NRG1, SLC3A2-NRG1) and the testing methodology. Submitting J9382 without NRG1 fusion test report attached is the #1 denial driver. Use a comprehensive RNA-based NGS panel (FoundationOne CDx, Tempus xR, Caris MI Tumor Seek) for detection.

What patient assistance is available for Bizengri?

The Bizengri Access Program from Merus (1-833-MERUS-4U / 1-833-637-8748) provides benefits investigation, prior authorization assistance, appeal support, and copay assistance. Eligible commercially insured patients may pay reduced out-of-pocket per infusion through the Bizengri Copay Program (excludes Medicare, Medicaid, federal program patients). Uninsured and underinsured patients meeting income criteria can apply to the Merus Patient Assistance Program for free product. Medicare patients should be referred to PAN Foundation, HealthWell Foundation, CancerCare, and Good Days for NSCLC and pancreatic cancer copay funds — verify open funds quarterly.

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

Source documents

FDA — BIZENGRI (zenocutuzumab-zbco) Prescribing Information
FDA-approved label, December 2024 accelerated approval; includes warnings (infusion-related reactions, ILD/pneumonitis, LV dysfunction), dosing, both approved indications
DailyMed — BIZENGRI Prescribing Information (Merus US, setid 2a33e782-...)
FDA-approved label revised Jan 17, 2025; NDC 83077-100-01 single-vial and 83077-100-02 2-vial carton; 375 mg / 18.75 mL single-dose vial; dilution and administration instructions; BOXED warning for embryo-fetal toxicity confirmed
FDA Drugs@FDA — Bizengri BLA 761352
Approval history: accelerated approval December 4, 2024 for NRG1 fusion-positive NSCLC and pancreatic adenocarcinoma based on eNRGy trial (NCT02912949)
FDA — Accelerated approval announcement (December 4, 2024)
Official FDA announcement: first FDA-approved therapy specifically for NRG1 fusion-positive solid tumors
ClinicalTrials.gov — eNRGy trial (NCT02912949)
Pivotal phase II basket trial supporting Bizengri accelerated approval in NRG1 fusion-positive cancers
CMS — Medicare Part B Drug ASP Pricing File
Q2 2026 quarterly file, effective April 1 – June 30, 2026; J9382 payment limit $33.567 per mg
CMS — HCPCS Quarterly Update
J9382 permanent code effective July 1, 2025; descriptor "Injection, zenocutuzumab-zbco, 1 mg"; 1 unit = 1 mg
Bizengri.com — HCP and Patient Portal
Manufacturer dosing/admin reference: 750 mg flat IV q14d, 4-hour first infusion, 2-hour subsequent
Bizengri Access Program (Merus)
Bizengri Access Program: benefits investigation, prior authorization assistance, copay program, PAP — 1-833-MERUS-4U
Merus N.V. — Corporate site
Manufacturer corporate site; Bizengri product information and pipeline
NCCN Clinical Practice Guidelines in Oncology — NSCLC + Pancreatic Adenocarcinoma (current versions)
NCCN compendium support for both NRG1 fusion-positive NSCLC and NRG1 fusion-positive pancreatic adenocarcinoma indications (Category 2A in post-progression molecular-targeted setting)
UnitedHealthcare — Oncology Medication Clinical Coverage Policy
Aetna CPB 1076 — Zenocutuzumab (Bizengri)
Aetna Clinical Policy Bulletin specific to Bizengri/zenocutuzumab; NRG1 fusion documentation and previously treated status criteria
FDA National Drug Code Directory
Schram et al., eNRGy trial primary analysis — Journal of Clinical Oncology
Peer-reviewed primary analysis of the eNRGy phase II basket trial supporting Bizengri's accelerated approval in NRG1 fusion-positive cancers

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 CPB 1076, BCBS)	Semi-annual	Manual review against published payer policy documents.
HCPCS / CPT / modifier rules	Annual	Reviewed against CMS HCPCS quarterly files and AMA CPT releases.
NDC, dosing, FDA label, indication list	Event-driven	Tied to manufacturer document version + FDA label revision date. Accelerated approval (Dec 2024) under active monitoring for confirmatory data.

Reviewer

SME-audited 2026-05-22 — corrections applied. This page was audited 2026-05-22 against DailyMed setid 2a33e782-fc75-4dba-b77c-a44536ac13a5 (Merus US label, revised Jan 17, 2025). Corrections applied: (1) Embryo-fetal toxicity reclassified as BOXED warning (was listed under Key warnings); (2) NDC corrected from 83077-0100-01 to canonical 10-digit 83077-100-01 single-vial plus 83077-100-02 2-vial carton; (3) infusion-reaction and ILD incidence rates added per label. Verify each cited source for high-stakes claims.

Change log

May 22, 2026 — SME audit. (1) Embryo-fetal toxicity confirmed as BOXED warning per DailyMed (was listed only as Key Warning); page updated to label it boxed. (2) NDC corrected to 83077-100-01 (single-vial) plus 83077-100-02 (2-vial carton) per Merus US Jan 17, 2025 label. (3) Infusion-reaction (13%, all G1–2, median onset 63 min) and ILD (1.1%) incidence added. Label revision date confirmed Jan 17, 2025.
May 21, 2026 — Initial publication. ASP data: Q2 2026 ($33.567 per mg). Manufacturer source: Merus Bizengri.com 2026. FDA label: December 2024 accelerated approval (BLA 761352). Two indications: NRG1 fusion-positive NSCLC and NRG1 fusion-positive pancreatic adenocarcinoma (both accelerated approval Dec 4, 2024). Cross-product unit/indication confusion vs Ziihera flagged.

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 is verified against the current FDA label revision. We do not paraphrase from billing-software vendor blogs.

Bizengri (zenocutuzumab-zbco) — HCPCS J9382

Instant Answer — the 5 things you need to bill J9382

Dosing & unit math FDA label verified May 2026

Adult dosing — both approved indications

Preparation

Premedication for infusion-related reactions

Worked example — standard 750 mg flat dose, full year

NDC reference FDA NDC Directory verified May 2026

NRG1 fusion testing — the universal coverage gate NCCN / payer policies verified May 2026

Validated detection panels

Common NRG1 fusion partners (document the specific partner in chart)

Administration codes CPT verified May 2026

Modifiers CMS verified May 2026

JZ — the rule on most Bizengri claims

Worked example — standard 750 mg dose

Worked example — dose-reduced 600 mg (Grade 3 toxicity recovery)

Modifier 25 — same-day E/M

340B modifiers (JG, TB)

ICD-10-CM by indication FY2026 verified May 2026

Common NSCLC C34 codes

Pancreatic adenocarcinoma C25 codes

Secondary metastatic site codes (add as appropriate)

Site of care & place of service Verified May 2026

Claim form field mapping Merus Reimbursement Guide 2026

Payer policy snapshot Reviewed May 2026

Step therapy

NCCN compendium support

Medicare reimbursement CMS Q2 2026 (live)

Q2 2026 payment snapshot — J9382

Coverage

Code history

Patient assistance — Bizengri Access Program (Merus) Merus verified May 2026

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Bizengri?

Is Bizengri the same as Ziihera?

What is the billing unit for J9382?

What dose of Bizengri is given and how often?

What administration CPT do I use for Bizengri?

What's the modifier for Bizengri? Do I need JW?

What is the Medicare reimbursement for J9382?

Why is NRG1 fusion documentation the most common denial?

What patient assistance is available for Bizengri?

Source documents

About this page

Refresh cadence

Reviewer

Change log

Methodology

Stop calculating Bizengri copays by hand.