Medications
Pegfilgrastim (Neulasta)
A long-acting white-blood-cell growth factor given as one injection under the skin after each chemotherapy cycle (Neulasta prefilled syringe, or the on-body injector worn after chemo) to lower the chance of infection from a low white blood cell count; it is also used after harmful radiation exposure.
How Medicare covers it
Usual path Part B (injections given by a clinician — J2506, see the Part B basis in this package). The Part D aggregation in this package is carried exactly as computed. Part A during a covered inpatient stay.
| Coverage details | |
|---|---|
| Part B status | CMS Part B Spending by Drug HCPCS file (RY26, data through 2024) carries J2506 (injection, pegfilgrastim, excludes biosimilar, 0.5 mg — Neulasta): the clinician-administered injection path is Part B. The biosimilar rows (Q5108 pegfilgrastim-jmdb Fulphila, Q5111 pegfilgrastim-cbqv Udenyca, Q5122 pegfilgrastim-apgf Nyvepria, Q5127 pegfilgrastim-fpgk Stimufend, Q5130 pegfilgrastim-pbbk Fylnetra) are different products and are explicitly NOT matched. |
| Medicare Advantage | Most Medicare Advantage plans that include drug coverage (MAPD plans) use the same formulary-and-tier system; the plan's own drug list decides coverage and copay — check the plan's formulary. |
| Medicare Supplement (Medigap) | Medicare Supplement (Medigap) plans sold today do not include prescription drug coverage; drug coverage comes from Part D or an MAPD plan. |
What it treats
To lower the chance of infection, shown as fever with a low white blood cell count (febrile neutropenia), in adults and children with cancers other than myeloid leukemias who are receiving strong chemotherapy that commonly causes that problem. It is also used to increase survival in people acutely exposed to radiation doses that suppress the bone marrow. It is not used to collect stem cells for transplant.
What it is for, in depth
Neulasta is supportive care for chemotherapy, not a cancer treatment itself. Many chemotherapy regimens drive white blood cell counts down about a week after each cycle, and a fever at that low point (febrile neutropenia) is an emergency that can force treatment delays. One Neulasta dose after each cycle shortens that low-count window for patients with non-myeloid cancers on chemotherapy with a high febrile-neutropenia risk. It is prescribed by the oncology team as part of the chemotherapy plan — given by prefilled syringe or by the wearable on-body injector — and it has a second, separate use after dangerous radiation exposure. This package covers only the originator Neulasta product; the biosimilar versions (Fulphila, Udenyca, Nyvepria, Stimufend, Fylnetra, Ziextenzo, Armlupeg) are different RxNorm ingredients, gated separately where they rank.
How it works
Pegfilgrastim is a long-acting form of filgrastim, a copy of the body's G-CSF growth factor. It tells the bone marrow to make more neutrophils, the white blood cells that fight bacterial infection. One dose lasts through the low point after a chemotherapy cycle because the pegfilgrastim molecule clears mainly when neutrophil counts recover.
How it is taken
One 6 mg injection under the skin once per chemotherapy cycle for adults and children weighing at least 45 kg (smaller children's doses are by weight), given at least 24 hours after chemotherapy and not in the 14 days before the next chemotherapy. It is given as a prefilled syringe, or by the on-body injector worn on the skin that delivers the dose about a day after it is applied. For radiation exposure, two 6 mg doses are given one week apart, starting as soon as possible after exposure.
Common side effects
The most common reactions (at least 5% more often than with placebo) were bone pain and pain in an arm or leg.
Serious warnings
Rare but serious risks include rupture of the spleen (new left upper belly or shoulder pain must be checked at once), acute respiratory distress syndrome (ARDS), serious allergic reactions including anaphylaxis, fatal sickle cell crises in people with sickle cell disorders, kidney inflammation (glomerulonephritis), capillary leak syndrome, very low platelet counts, inflammation of the aorta, and — in breast and lung cancer patients treated with chemotherapy and/or radiation — myelodysplastic syndrome and acute myeloid leukemia, which are monitored for. The on-body injector uses acrylic adhesive and can fail to deliver, so patients are told to report any suspected failure.
Who should be careful
Neulasta must not be used by anyone with a history of a serious allergic reaction to pegfilgrastim or filgrastim. People with sickle cell disorders, and anyone who develops fever, breathing problems, or left-sided upper belly or shoulder pain after a dose, need prompt medical review.
Major interactions
The Neulasta label does not list major drug interactions; its interaction-type warnings concern timing with chemotherapy (not between 14 days before and 24 hours after chemotherapy) and the acrylic-adhesive allergy warning for the on-body injector.
Why it is in its tier
Neulasta shows the split coverage typical of a clinician-given biologic: its usual Medicare path is Part B (J2506), and in the Part D data it is listed by only 25.3% of plans — but where Part D plans do list it, its most common tier is Tier 5, in 95.25% of listing plans. Tier 5 is the specialty tier, which usually means coinsurance — a percentage of a high price — rather than a fixed copay. CMS dashboard data put average spending at $21,942.21 per beneficiary in 2024, a high cost level driven by one dose per chemotherapy cycle; that figure is a program average, not your copay. The tier shown is the most common placement only, and individual plans vary.
What official patient guides say
Pegfilgrastim injection comes as a solution (liquid) in prefilled injection syringes and a prefilled autoinjector, to inject under the skin; some types also come in a prefilled on-body injector applied to the skin. How often you receive it and how long treatment lasts depend on your condition and how your body responds, and your doctor will tell you exactly when you should use it. It may be given by a nurse or other healthcare provider, or you may be taught to inject it yourself at home or manage the on-body device, which is applied the day before the dose and automatically injects it about 27 hours later. Use it exactly as directed; do not shake the syringes or autoinjectors, and always look at the solution first — do not use it if the expiration date has passed or the liquid has particles or looks cloudy or discolored. If you inject it at home and forget to inject it on schedule, the page tells you to talk to your doctor about what you should do. Keep the medication in the carton it came in, out of the reach of children, stored in the refrigerator; do not freeze it, though a syringe that was accidentally frozen may thaw in the refrigerator, and a syringe frozen a second time should be thrown away. The Neulasta prefilled syringe may be kept at room temperature for up to 48 hours, and the medication should be kept away from direct sunlight; dispose of unneeded medication through a medicine take-back program rather than flushing it.
Source: MedlinePlus — Pegfilgrastim
Part D formulary coverage
| Formulary summary | |
|---|---|
| Most common tier | 5 |
| Plans listing this drug | 1390 |
| Total Part D plans | 5495 |
| Share of plans listing it | 25.3 |
| Formularies listing it | 50 |
| Tier | Plans |
|---|---|
| Tier 1 | 29 plans |
| Tier 4 | 37 plans |
| Tier 5 | 1324 plans |
Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.
What you pay
| With Medicare Part D | |
|---|---|
| Most common tier | Tier 5 |
| Typical copay | $0 — half of plans charge between $0 and $0 |
| Typical coinsurance | 26.0% of the price |
| Based on | 1285 plans that cover this drug · 2027 plan year |
A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.
Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-08
Similar medications
Other medications in the same FDA pharmacologic class (Leukocyte Growth Factor):
Read next
Part D spending averages (2024)
| Brand name | Generic name | Total claims 2024 | Total spending 2024 | Total beneficiaries 2024 | Rank by beneficiaries 2024 |
|---|---|---|---|---|---|
| Neulasta | PEGfilgrastim | 7279 | 5.31221e+07 | 2421 | 1455 |
| Neulasta Onpro | PEGfilgrastim | 6609 | 4.31518e+07 | 1915 | 1542 |
Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30
Companies covering this drug
1,390 plans from 104 companies list this drug on a formulary for 2027. Search by company or plan name, or filter by tier. Cost sharing is the plan's published amount for this drug's tier in the initial coverage stage (1-month retail supply), where the plan publishes it; a blank means the plan does not publish it.
| Company | Plan | Tier | Copay | Coinsurance |
|---|
A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.
Coverage and costs change. Drug lists (formularies), tiers, and copays can change during the year and differ by plan. Always check with your insurance company or plan directly to confirm what is covered and what you will pay.
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