HCPCS
J1442
1 unit = 1 mcg
Phase 1
Identify what you're billing
Reference Neupogen plus four biosimilars. One unit basis (1 mcg). Weight-based daily SC dosing.
About Neupogen (filgrastim) FDA label + Amgen reference verified 2025–2026
Neupogen is the reference brand for filgrastim, a recombinant granulocyte colony-stimulating factor (G-CSF) manufactured by Amgen Inc. and first FDA-approved in February 1991. Filgrastim is dosed daily SC (typically 5 mcg/kg/day, weight-based) until post-nadir absolute neutrophil count (ANC) recovery — usually 5–7 days per chemotherapy cycle.
FDA-approved indications include: (1) reducing the incidence and duration of neutropenia in patients receiving myelosuppressive chemotherapy for non-myeloid malignancies; (2) reducing the time to neutrophil recovery and the duration of fever following induction or consolidation chemotherapy for AML; (3) reducing the duration of neutropenia and related sequelae in patients with non-myeloid malignancies undergoing bone marrow transplantation (BMT); (4) mobilization of autologous hematopoietic progenitor cells into peripheral blood for collection by leukapheresis (PBPC mobilization); (5) chronic administration to reduce infections in patients with severe chronic neutropenia (congenital, cyclic, or idiopathic); and (6) increasing survival in patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Syndrome of Acute Radiation Syndrome — HSARS).
Four FDA-approved biosimilars currently share the filgrastim molecule: Zarxio (Q5101), Nivestym (Q5110), Releuko (Q5125), and Nypozi (FDA-approved March 2024 — no permanent Q-code in the Q2 2026 CMS ASP file). Most major commercial payers now prefer a biosimilar over reference Neupogen for new starts. Filgrastim is mechanistically and clinically distinct from the long-acting pegylated form pegfilgrastim (Neulasta J2506), which is given as a single dose per chemo cycle rather than daily.
Five filgrastim products — the disambiguation table CMS HCPCS + FDA verified May 2026
One reference brand and four FDA-approved biosimilars. All share one unit basis (1 mcg), one mechanism (G-CSF), and one weight-based dosing convention. Each biosimilar has its own HCPCS code, NDC, and manufacturer; Nypozi lacks a permanent Q-code in the current CMS ASP file.
| HCPCS | Brand | Suffix | Mfr | HCPCS descriptor | Q2 2026 ASP+6% / mcg |
|---|---|---|---|---|---|
J1442 |
Neupogen (reference) | (reference) | Amgen | "Injection, filgrastim (G-CSF), excludes biosimilars, 1 microgram" | $1.016 |
Q5101 |
Zarxio | filgrastim-sndz | Sandoz | "Injection, filgrastim-sndz, biosimilar, (Zarxio), 1 microgram" | $0.354 |
Q5110 |
Nivestym | filgrastim-aafi | Pfizer | "Injection, filgrastim-aafi, biosimilar, (Nivestym), 1 microgram" | $0.284 |
Q5125 |
Releuko | filgrastim-ayow | Amneal / Kashiv BioSciences | "Injection, filgrastim-ayow, biosimilar, (Releuko), 1 microgram" | $0.320 |
| (pending) | Nypozi | filgrastim-txid | Tanvex BioPharma | FDA-approved March 2024 as biosimilar to Neupogen. No permanent CMS Q-code in Q2 2026 ASP file — bill J1442 NOC with documentation, or pending Q-code per quarterly HCPCS update. | verify CMS |
Reference-error patterns to avoid:
- Unit basis: J1442 and all three biosimilar Q-codes are 1 mcg per unit, not 1 mg. A 300 mcg dose is 300 units (not 0.3). Defaulting to mg would under-bill by 1,000×.
- Q5125 is Releuko (filgrastim), NOT Stimufend (pegfilgrastim): CMS assigned Q5125 to Releuko, the filgrastim biosimilar. Stimufend, the pegfilgrastim biosimilar from Fresenius Kabi, is
Q5127. Easy to confuse — if you grabbed Q5125 expecting pegfilgrastim, stop and verify the brand on the dispensed product. - J1442 is "excludes biosimilars": J1442 covers Neupogen and any non-biosimilar reference filgrastim. Each FDA-approved biosimilar has its own Q-code — do not bill J1442 when the patient received Zarxio (Q5101), Nivestym (Q5110), or Releuko (Q5125).
- Filgrastim ≠ pegfilgrastim: Daily SC filgrastim (J1442 + biosimilars) is not interchangeable with q-cycle SC pegfilgrastim (J2506 + biosimilars). Mixing the codes is a clinical-policy denial — see Neulasta family for the long-acting side.
Dosing & timing FDA label + NCCN HGF Guidelines
Weight-based daily SC dosing. Indications drive the mg/kg/day target. Round per institutional protocol; bill in microgram units (1 unit = 1 mcg).
| Indication | Dose | Route & schedule | Duration |
|---|---|---|---|
| Myelosuppressive chemo (FN prophylaxis or treatment) | 5 mcg/kg/day | SC daily (preferred) or short IV infusion | Start ≥24 hr after chemo; continue until post-nadir ANC ≥10,000/mm³ (typically 5–7 days) |
| Induction / consolidation chemo for AML | 5 mcg/kg/day | SC or short IV | Start ≥24 hr after chemo; until ANC recovery |
| Bone marrow transplant (BMT) | 10 mcg/kg/day | IV infusion over 4 or 24 hr (per protocol) | Start ≥24 hr after transplant; titrate to ANC |
| Peripheral blood progenitor cell (PBPC) mobilization | 10 mcg/kg/day | SC (bolus or continuous infusion); start 4 days before leukapheresis | Continue through leukapheresis (typically 6–7 days) |
| Severe chronic neutropenia — congenital | 6 mcg/kg twice daily | SC, divided BID | Chronic; titrate to maintain ANC |
| Severe chronic neutropenia — cyclic / idiopathic | 5 mcg/kg/day | SC daily | Chronic; titrate to maintain ANC |
| HSARS (Acute Radiation Syndrome) | 10 mcg/kg/day | SC daily | Continue until ANC >1,000/mm³ for 3 consecutive CBCs |
Dosing math — typical 5 mcg/kg/day SC
# Adult 70 kg, primary FN prophylaxis
patient_weight = 70 kg
dose_per_kg = 5 mcg/kg/day
daily_dose = 70 × 5 = 350 mcg/day
billed_units_day = 350 / 1 = 350 units of J1442 per daily SC injection
cycle (7 days) = 350 × 7 = 2,450 mcg total per cycle (2,450 units total)
# Vial selection (single-dose 300 mcg or 480 mcg)
For 350 mcg daily dose:
Option A: 1 × 480 mcg vial → 350 mcg administered, 130 mcg discarded (JW)
Option B: 1 × 300 mcg vial + 1 × 480 mcg vial → combined waste accounting per CMS guidance (uncommon)
Preferred: single 480 mcg vial; bill 350 units (admin) + 130 units (JW) = full vial accounted for.
Timing rules:
- Begin filgrastim at least 24 hours after cytotoxic chemotherapy — concurrent dosing amplifies myelosuppression.
- Stop at least 24 hours before the next planned chemotherapy administration.
- For SCN (chronic use), do not exceed the FDA-labeled maximum daily dose; obtain baseline and periodic ANC and CBC.
- Pre-filled syringes and vials are single-dose containers — any unused volume must be discarded (drives JW modifier).
NDC reference Amgen package configurations verified 2025
Neupogen ships in single-dose prefilled syringes (PFS) and single-dose vials in two strengths. Biosimilar NDCs vary by manufacturer — verify against the dispensed product label.
| NDC | Strength | Package size | Units/container |
|---|---|---|---|
55513-530-10 | 300 mcg / 0.5 mL | Single-dose prefilled syringe (PFS), 10 ct | 300 units (1 mcg = 1 unit) |
55513-924-10 | 480 mcg / 0.8 mL | Single-dose prefilled syringe (PFS), 10 ct | 480 units |
55513-546-10 | 300 mcg / 1 mL | Single-dose vial, 10 ct | 300 units |
55513-209-10 | 480 mcg / 1.6 mL | Single-dose vial, 10 ct | 480 units |
61314-318-01 | 300 mcg / 0.5 mL | Zarxio (Sandoz, Q5101) PFS — reference SKU | 300 units |
00069-0291-01 | 480 mcg / 0.8 mL | Nivestym (Pfizer, Q5110) PFS — reference SKU | 480 units |
Always reconcile the NDC on the dispensed product against the HCPCS code on the claim. Most denials in the filgrastim family come from a biosimilar product paired with the wrong J/Q code (e.g., Zarxio dispensed, J1442 billed) or vice versa.
Phase 2
Code the claim
CPT admin, modifiers, ICD-10, site of care, claim-form fields.
CPT administration codes AMA CPT 2026 + NCCI verified
Filgrastim is a supportive-care biologic, NOT a cytotoxic antineoplastic. The correct SC admin code is 96372 — not 96401.
| CPT | Descriptor | When to use |
|---|---|---|
96372 |
Therapeutic, prophylactic, or diagnostic injection (specify substance or drug); subcutaneous or intramuscular | Primary admin code for in-clinic SC filgrastim. Filgrastim is a non-cytotoxic biologic. |
96365 |
IV infusion, for therapy/prophylaxis/diagnosis; initial, up to 1 hour | Short IV infusion (BMT, PBPC IV protocols) |
96366 |
IV infusion, each additional hour | Continuous IV PBPC mobilization beyond the initial hour |
| (no admin) | — | Patient self-administered at home from specialty-pharmacy dispensed PFS — no facility/provider admin billable; J1442 typically routes via pharmacy benefit (NDC), not medical benefit |
Common error: billing 96401 for filgrastim. 96401 is "chemotherapy admin, subcutaneous or
intramuscular; non-hormonal anti-neoplastic." Filgrastim is not an antineoplastic — it is supportive
care. Billing 96401 will trigger an NCCI / payer-policy edit. Note that this differs from pegfilgrastim
(Neulasta J2506), where most payers DO accept 96401 because pegylated
filgrastim is classified by billers as a chemo-support biologic in that family's policies.
Modifiers CMS JW/JZ guidance (eff. 7/1/2023)
Filgrastim ships in fixed-strength single-dose containers (300 mcg or 480 mcg). Doses are weight-based, so partial-vial discard (JW) is the rule, not the exception.
| Modifier | When to apply |
|---|---|
JW |
Drug discarded from a single-dose container. Common for filgrastim because vials are 300 or 480 mcg and the calculated dose rarely matches exactly. Required by CMS effective 7/1/2023. |
JZ |
Single-dose container, no drug discarded. Use when the calculated dose exactly fills the vial (e.g., 300 mcg dose from a 300 mcg PFS). Required by CMS effective 7/1/2023. |
JG / TB |
340B-acquired drug. Apply when the dispensing institution acquired filgrastim via the 340B Drug Pricing Program (JG for Medicare, TB for some Medicaid plans — verify per state). |
| Biosimilar suffix (descriptor only) | The four-letter biosimilar suffix (-sndz, -aafi, -ayow, -txid) is part of the FDA proper name and the HCPCS descriptor — not a CPT modifier on the claim line. Modifier ZA/ZB/ZC historically used for biosimilar identification was retired by CMS in 2018; use the correct Q-code instead. |
Worked JW example — 350 mcg dose from a 480 mcg PFS
# Patient: 70 kg adult, primary FN prophylaxis, day 3 of 7-day cycle
ordered_dose = 70 kg × 5 mcg/kg = 350 mcg
vial_drawn = 1 × 480 mcg/0.8 mL PFS
administered = 350 mcg
discarded = 480 − 350 = 130 mcg
# Claim lines (CMS-1500 / 837P)
Line 1: J1442 × 350 units (no modifier — administered drug)
Line 2: J1442 × 130 units with modifier JW (wastage)
# Documentation in chart for audit defense
- patient weight (70 kg) and date weighed
- ordered dose (350 mcg, 5 mcg/kg)
- vial drawn (480 mcg/0.8 mL, NDC 55513-924-10, lot)
- administered volume / dose, discarded volume / dose
- single-use container, single patient
JZ scenario: 60 kg patient, 5 mcg/kg/day = 300 mcg ordered. Drawn from a 300 mcg/0.5 mL PFS
(NDC 55513-530-10). Bill J1442 × 300 units with JZ. No second line; no JW.
ICD-10 by indication CMS LCDs + NCCN HGF Guidelines
Indication-mapped ICD-10s. Most payers require both a primary diagnosis (the chemo-treated cancer or the chronic neutropenia diagnosis) and a secondary diagnosis documenting the neutropenia/encounter context.
| ICD-10 | Descriptor | Use when |
|---|---|---|
D70.1 | Agranulocytosis secondary to cancer chemotherapy | Chemo-induced neutropenia (most common pairing) |
D70.2 | Other drug-induced agranulocytosis | Non-chemo drug-induced neutropenia |
D70.0 | Congenital agranulocytosis | Severe congenital neutropenia (chronic SCN) |
D70.4 | Cyclic neutropenia | Severe cyclic neutropenia (chronic SCN) |
D70.8 | Other neutropenia (incl. idiopathic) | Severe idiopathic neutropenia (chronic SCN) |
D70.9 | Neutropenia, unspecified | When specific type is not documented (use sparingly) |
R50.81 | Fever presenting with conditions classified elsewhere | Documented febrile neutropenia episode (often with D70.1) |
Z51.11 | Encounter for antineoplastic chemotherapy | Secondary code identifying the chemo encounter context |
Z51.81 | Encounter for therapeutic drug level monitoring | SCN monitoring visits / serial ANC checks |
C00–D49 | Primary malignancy (varies) | The chemo-treated cancer ICD-10 as the primary diagnosis |
T66.XXXA | Radiation sickness, unspecified, initial encounter | HSARS (Acute Radiation Syndrome) indication |
Site of care & place-of-service (POS) Payer SOC steerage verified 2025–2026
Filgrastim is unusual in that the same drug is routinely billed under both the medical and pharmacy benefits depending on where it is administered. Most 2026 commercial payers steer to home self-administration to lower site-of-care cost.
| Setting | POS | Benefit channel | Notes |
|---|---|---|---|
| Office-based infusion (oncology practice) | 11 | Medical (J1442 + 96372) | Most common for in-clinic SC during chemo cycle |
| Hospital outpatient (HOPD) | 22 | Medical (J1442 + 96372) | OPPS APC payment; many payers SOC-steer AWAY from HOPD |
| Inpatient hospital | 21 | Inpatient DRG-bundled | Not separately billable; included in DRG (BMT, induction) |
| Patient home (self-administered) | 12 | Pharmacy (Part D / commercial Rx) | Specialty pharmacy dispenses PFS; patient or caregiver injects SC. Most common 2026 channel for commercial chemo prophylaxis. |
| Skilled nursing facility | 31 / 32 | Bundled under Part A consolidated billing (Medicare) | Usually not separately billable on outpatient claims during SNF stay |
Two-benefit reality: A single patient may receive filgrastim through pharmacy benefit
(home self-admin, NDC-based) for one cycle and medical benefit (in-clinic admin, J1442) for another cycle
depending on clinic workflow. Reconcile against the dispensing record — never assume J1442 is the
billable code without checking how the drug was actually dispensed and administered.
Claim-form fields (CMS-1500 / 837P) CMS-1500 v02/12 verified 2026
Filgrastim adds two unusual claim-form considerations: NDC reporting (Box 24A shaded area) and JW/JZ on every J1442 line.
| Box | Field | Filgrastim guidance |
|---|---|---|
| 21 | Diagnosis pointer | Primary cancer ICD-10 + neutropenia code (D70.1 typical); pointer A linked to drug line |
| 24A (shaded) | NDC reporting | Many payers (esp. Medicaid + commercial managed care) require N4 + NDC + unit qualifier (UN or ML) + quantity in the shaded portion of the drug-line service-date row |
| 24D | HCPCS / CPT | J1442 (or Q5101/Q5110/Q5125 for biosimilar) + JW or JZ modifier on every line |
| 24E | Diagnosis pointer | Point to neutropenia (D70.1) + chemo encounter (Z51.11) where applicable |
| 24G | Days or units | Microgram unit count (1 mcg = 1 unit). 350 mcg dose = 350 units. |
| 24J | Rendering provider NPI | NPI of the supervising physician for office-based admin (incident-to rules apply) |
Example claim-line structure (CMS-1500)
# 70 kg adult, primary FN prophylaxis, day 3 of 7-day cycle
# Admin = 350 mcg from a 480 mcg PFS (NDC 55513-924-10)
24A row 1 (admin):
Date of svc | POS 11 | HCPCS: 96372 | Diag pointer: A
24A row 2 (drug - administered):
Shaded: N4 55513092410 UN 350
HCPCS: J1442 | Units: 350 | Mods: (none) | Diag pointer: A
24A row 3 (drug - wastage):
Shaded: N4 55513092410 UN 130
HCPCS: J1442 | Units: 130 | Mods: JW | Diag pointer: A
Box 21: A=D70.1, B=Z51.11, C=C50.911 (or actual cancer dx)
Phase 3
Get paid
Payer biosimilar mandates, Medicare ASP, manufacturer patient assistance.
Payer policies — 2026 biosimilar preference UHC / Aetna / Cigna / BCBS verified May 2026
Filgrastim biosimilar mandates are now near-universal at major commercial payers. Most plans steer to a single preferred biosimilar plus home self-administration.
| Payer | PA required? | Preferred product | Key criteria |
|---|---|---|---|
| UnitedHealthcare commercial | Yes | Biosimilar (Q-code; varies by plan year) | Cancer dx + chemo regimen with FN risk ≥20% (per NCCN) OR prior FN episode; biosimilar mandate; SOC steerage to home self-admin via Optum specialty Rx |
| UHC Medicare Advantage (Part B) | Yes (step) | Biosimilar via Medicare Part B step therapy | Step requires trial of biosimilar before reference Neupogen J1442 |
| Aetna commercial | Yes | Biosimilar (Q5101 or Q5110 typically preferred) | FN risk threshold or documented neutropenia; biosimilar mandate for new starts |
| Cigna commercial | Yes | Biosimilar via Accredo / Express Scripts specialty | FN risk threshold; specialty pharmacy fill; pharmacy benefit channel preferred for SC self-admin |
| BCBS plans | Yes (varies) | Biosimilar (plan-specific Q-code) | FEP and most state plans now require biosimilar first; some retain institutional Neupogen for inpatient/HOPD |
| Medicare LCD (traditional) | Coverage rules | Any FDA-approved filgrastim product | FDA-approved indication + appropriate ANC / chemo regimen documentation; reimbursement at ASP+6% |
| Medicaid (state-by-state) | Varies | Varies (often biosimilar preferred) | State FFS PDL determines preferred Q-code; managed-Medicaid follows commercial-style PA criteria |
Step therapy in 2026: Even when reference Neupogen J1442 is "covered," the payer's step
edit may require documented trial and failure (or contraindication) of a biosimilar before paying the J1442
claim. Build the PA pre-check around the patient's plan year + preferred Q-code list — do not assume
prior years' authorization carries forward.
Medicare reimbursement CMS Part B ASP file Q2 2026 (live-bound)
ASP+6% per microgram. Live binding to the CareCost ASP data layer; refreshes when CMS publishes the next quarterly file.
Q2 2026 ASP+6% snapshot
J1442 per mcg
$1.016
Reference Neupogen (Amgen); 1 unit = 1 mcg
350 mcg dose (70 kg)
$355.60
5 mcg/kg/day × 70 kg × ASP+6%
7-day cycle
$2,489.20
350 mcg/day × 7 days, pre-sequestration
Sequestration: Medicare applies a ~2% across-the-board reduction to most Part B drug payments. Net payment to provider for a 7-day cycle approximates ~$2,439. ASP refreshes quarterly. Biosimilar Q-codes price at substantially lower per-mcg ASP: Zarxio Q5101 $0.354/mcg · Nivestym Q5110 $0.284/mcg · Releuko Q5125 $0.320/mcg.
Next CMS update: July 1, 2026 (Q3 file). Watch for biosimilar consolidations — CMS has been narrowing the gap between reference J1442 and biosimilar Q-codes in recent quarters as biosimilar market share grows.
Patient assistance — Amgen Assist 360 / SafetyNet Amgen verified 2025–2026
Amgen consolidates Neupogen support under Amgen Assist 360 (HCP-facing coordination) and Amgen Safety Net Foundation (patient eligibility for free product).
| Program | Eligibility | Benefit | Enrollment |
|---|---|---|---|
| Neupogen Co-pay Program | Commercially insured patients (excludes Medicare, Medicaid, Tricare, VA, ChampVA); US residents | Reduces out-of-pocket co-pay (per-dose maximum; annual maximum varies by program year) | neupogen.com · amgenassist360.com · 1-888-4ASSIST (1-888-427-7478) |
| Amgen Safety Net Foundation | Uninsured or underinsured patients meeting Foundation income criteria (typically ≤500% FPL; reviewed annually) | Free Neupogen product for eligible patients (replacement for the prescription) | amgensafetynetfoundation.com · 1-888-762-6436 |
| Amgen Assist 360 (HCP coordination) | Provider offices coordinating PA, appeals, benefit investigations | Benefit investigations, prior-auth support, copay/PAP enrollment coordination | 1-888-4ASSIST (1-888-427-7478) |
| HealthWell Foundation (3rd-party, when funded) | Disease-state-specific funds; income ≤500% FPL typical | Co-pay assistance for filgrastim/pegfilgrastim in oncology supportive care | healthwellfoundation.org (verify open fund) |
Biosimilar manufacturers run separate patient-support programs: Sandoz One Source (Zarxio Q5101), Pfizer Patient Assistance (Nivestym Q5110), and Amneal access programs (Releuko Q5125). Match the support program to the dispensed product, not the reference brand.
Phase 4
Fix problems
Top denial reasons and FAQ.
Common denials & how to fix them Payer denial-pattern analysis 2025–2026
| Denial reason | Root cause | Fix / appeal strategy |
|---|---|---|
| Prior auth not obtained / missing ANC documentation | Filgrastim PA submitted without ANC labs or without FN-risk regimen documentation | Resubmit with: ordered chemo regimen + NCCN FN-risk category (target ≥20%); baseline + cycle-day ANC; documented neutropenic fever (R50.81) if secondary prophylaxis; or prior cycle FN episode |
| Biosimilar mandate — J1442 denied for new start | Plan now requires biosimilar Q-code (Q5101 / Q5110 / Q5125) first | Switch order to preferred biosimilar OR document clinical reason for reference Neupogen (intolerance to biosimilar excipient, prior failure, specific institutional contract); submit medical-necessity letter |
| Site-of-care denial (HOPD → home steerage) | Plan requires home self-administration via specialty pharmacy; in-clinic admin not covered | Coordinate with payer-preferred specialty pharmacy (Optum, Accredo, etc.) for home dispensing; bill J1442 only when in-clinic admin is clinically necessary (pediatric, frailty, first-dose monitoring) and supports a medical-necessity exception |
| Wrong J/Q code on claim (NDC-HCPCS mismatch) | Dispensed Zarxio (Q5101) but claim submitted as J1442 | Pull dispense record → correct HCPCS to match dispensed product → resubmit with corrected NDC in shaded 24A |
| Wrong unit count (mcg vs. mg confusion) | Provider billed 0.3 units for a 300 mcg dose (treating as mg) instead of 300 units | Correct unit count to micrograms (1 unit = 1 mcg). Verify CDM/charge master conversion factor — the 1000× error is a recurring chargemaster bug |
| JW/JZ modifier missing on single-dose container claim | CMS 7/1/2023 rule requires JW (waste) or JZ (no waste) on every single-dose container claim | Append JW (with separate wastage line) or JZ (no wastage) per actual administration; document vial size + admin volume in chart |
| Concurrent chemo dosing (within 24 hr) | Filgrastim administered <24 hr after chemo (label violation) | Coverage often denied for that day; reschedule per label and document; appeals rarely successful when chart shows label violation |
FAQ Billing & coding professionals
Neupogen vs. Neulasta — which J-code do I bill?
Bill J1442 for filgrastim (Neupogen) — 1 unit = 1 mcg, daily × 5–7 days per
cycle. Bill J2506 for pegfilgrastim (Neulasta) — 1 unit = 0.5 mg, once per cycle. They
are different molecules with different schedules, different units, and different HCPCS codes. Biosimilars
exist for both. See Neulasta family reference for the long-acting side.
Are filgrastim biosimilars equivalent to Neupogen?
Yes — Zarxio (Q5101), Nivestym (Q5110), Releuko (Q5125), and Nypozi (FDA 2024) are all FDA-approved as biosimilars to Neupogen, meaning they are highly similar with no clinically meaningful differences in safety, purity, or potency. None of the four carries an FDA interchangeability designation (a separate, higher-bar status), so pharmacy-level substitution depends on state law and prescriber choice. Dosing and administration are identical to reference Neupogen.
Can patients self-administer Neupogen at home?
Yes — this is now the most common channel for commercial chemo prophylaxis. The 300 mcg and 480 mcg prefilled syringes are dispensed via specialty pharmacy and the patient (or caregiver) injects SC at home. When dispensed through the pharmacy benefit, billing is NDC-based (not J1442). When administered in clinic, bill J1442 + 96372 under the medical benefit. Most 2026 payers steer to home self-administration to lower site-of-care cost.
What CPT admin code applies to SC filgrastim?
96372 (therapeutic SC injection, non-chemo) is the correct admin code — NOT
96401. Filgrastim is a supportive-care biologic, not a cytotoxic antineoplastic. Note that the
opposite is true for pegfilgrastim (Neulasta), where most payers do accept 96401 because the pegylated
form is classified by billers as a chemo-support biologic.
What ANC threshold is required for coverage?
There is no single threshold. For primary prophylaxis, most payers require documentation that the chemo regimen carries FN risk ≥20% (per NCCN), independent of baseline ANC. For secondary prophylaxis or treatment, payers typically require documented neutropenia (ANC <500/mm³ or <1,000/mm³ predicted to fall <500) or a prior FN episode. For severe chronic neutropenia, coverage requires baseline ANC <500/mm³ with documented infections. Submit ANC labs with the claim or PA.
Why are most 2026 payers preferring biosimilars?
Pricing. Q2 2026 ASP+6%: reference Neupogen J1442 = $1.016/mcg; Nivestym Q5110 = $0.284/mcg (about a 72% reduction at the unit level). On a 350 mcg daily dose for a 7-day cycle, that translates to roughly $2,489 (J1442) vs. roughly $696 (Q5110) before sequestration. Major commercial payers (UHC, Aetna, Cigna, most BCBS) now mandate a biosimilar first.
What is the Q2 2026 Medicare reimbursement for J1442?
Q2 2026 ASP+6% for J1442 is $1.016 per mcg. A typical 350 mcg/day adult dose (70 kg × 5 mcg/kg) reimburses approximately $355.60/day; a 7-day cycle is approximately $2,489.20 before the ~2% Medicare sequestration adjustment. ASP refreshes quarterly — next update July 1, 2026 for Q3.
Does JW apply to filgrastim?
Yes — and JW is the rule rather than the exception. Filgrastim vials and PFS come in fixed strengths (300 mcg or 480 mcg), but doses are weight-based, so partial-vial discard is common. A 350 mcg dose drawn from a 480 mcg PFS produces 130 mcg of wastage → bill Line 1 J1442 × 350 units, Line 2 J1442 × 130 units with JW. When the dose exactly matches the container (e.g., 300 mcg dose from a 300 mcg PFS), use JZ instead.
What warnings & precautions apply to Neupogen?
Neupogen has no FDA boxed warning. The label carries Warnings & Precautions for: splenic rupture (can be fatal), ARDS, anaphylaxis, sickle cell crises (avoid in SCD), glomerulonephritis, alveolar hemorrhage in healthy donors, capillary leak syndrome, and possible MDS/AML risk with chronic use in SCN. Do not administer within 24 hours before or after cytotoxic chemotherapy.
Source documents
- FDA Neupogen label (BLA 103353)
- AAPC — HCPCS J1442 (filgrastim, reference)
- AAPC — HCPCS Q5101 (Zarxio / filgrastim-sndz)
- AAPC — HCPCS Q5110 (Nivestym / filgrastim-aafi)
- AAPC — HCPCS Q5125 (Releuko / filgrastim-ayow)
- Amgen — Neupogen product site
- Amgen Assist 360
- Amgen Safety Net Foundation
- NCCN — Hematopoietic Growth Factors Clinical Practice Guidelines
- ASCO Clinical Practice Guideline — Update on Use of WBC Growth Factors
- UnitedHealthcare — Commercial Medical Drug policies (oncology supportive care)
- CMS — Medicare Part B Drug ASP Pricing File
- CMS — HCPCS quarterly update file
- CMS — JW / JZ modifier guidance
- FDA — Biosimilar product information (filgrastim family)