HCPCS code Q5101: Zarxio injection, per 1 mcg2026 Medicare rate & RVUs in Illinois
Reports filgrastim-sndz, a filgrastim biosimilar used to support neutrophil recovery, with each unit representing 1 microgram of drug.
CMS doesn’t publish an office rate for Q5101 in Illinois.
Medicare allowed amount for participating (non-QP) physicians, before deductible, coinsurance and claim adjustments. Not a patient’s bill or a hospital charge.
Your location
On this page 9 sections
What Q5101 covers
Q5101 identifies Zarxio (filgrastim-sndz), a biosimilar granulocyte colony-stimulating factor used to increase neutrophils. Clinicians commonly use filgrastim products for patients with chemotherapy-related neutropenia, certain other severe neutropenia conditions, or to mobilize blood-forming stem cells. Administration may be subcutaneous or intravenous, depending on the clinical use and treatment plan. Oncology practices and infusion centers commonly report the drug code for the product administered.
CMS assigns this code physician fee schedule status E, meaning it is excluded from the physician fee schedule; when Medicare covers it, payment is under another method. CMS classifies it as a Part B drug, generally priced from quarterly Average Sales Price files when covered, and assigns special Medicare coverage instructions. Each unit represents 1 microgram of filgrastim-sndz, so report units based on the administered drug dose.
This summary was written with AI assistance from CMS physician fee schedule data and checked against the CMS billing rules shown here. Rates on this page come directly from CMS files.
Where Q5101 pays more and less in Illinois
The same RVUs, adjusted for each area’s costs. Open a locality for its calculation, history and nearby areas.
| Payment locality | Office | Facility |
|---|---|---|
| Chicago, IL | Unavailable | Unavailable |
| East St. Louis, IL | Unavailable | Unavailable |
| Rest of Illinois | Unavailable | Unavailable |
| Suburban Chicago, IL | Unavailable | Unavailable |
How the Q5101 rate is calculated
Each of Q5101’s three RVUs is multiplied by a geographic index (GPCI) for the payment locality, added up, and multiplied by the conversion factor. Drag the indexes or enter a ZIP to see what moves the rate.
How the rate is built · Q5101
RVUs × geographic indexes × conversion factor
Work0.00
0.00 RVUs× 1.000 GPCI
Practice expense0.00
0.00 RVUs× 1.000 GPCI
Malpractice0.00
0.00 RVUs× 1.000 GPCI
Adjusted RVUs
0.0000
Conversion factor
$33.4009
Medicare rate
$0.00
Every GPCI starts at 1.000, the national rate. Enter a ZIP or drag a slider.
Payment rules and modifiers for Q5101
Q5101 has no global surgery period, no multiple-procedure, bilateral or assistant-at-surgery adjustment, and no professional/technical split. What changes the payment is where the service happens: the place of service on the claim decides whether Medicare pays the office or the facility rate.
Place of service · Q5101
Which rate does Medicare pay?
The POS code on the claim line (CMS-1500 box 24B).
POS 11 · non-facility rate · national
—
Q5101 isn’t priced in this setting.
Q5101 compared with similar codes
Compare codes · National
5 codes, side by side
How to choose
- Q5110NivestymPer 1 mcg
- Q5110 identifies Nivestym, a different filgrastim biosimilar. Q5101 is specific to filgrastim-sndz (Zarxio).
- Q5125Releuko injectionPer 1 mcg
- Q5125 identifies Releuko, not Zarxio. Select the code for the filgrastim product actually administered.
- Q5108Fulphila injectionPer 0.5 mg
- Q5108 is for pegfilgrastim-jmdb (Fulphila), a different, longer-acting drug. Q5101 is for filgrastim-sndz and counts each microgram.
- J1442Filgrastim injectionPer 1 microgram
- J1442 identifies filgrastim rather than the filgrastim-sndz biosimilar. Use Q5101 when the administered product is Zarxio.
Q5101 billing questions
When should Q5101 be used instead of another filgrastim code?
Use Q5101 for filgrastim-sndz (Zarxio). Other filgrastim biosimilar products have their own HCPCS codes, including Q5110 for Nivestym and Q5125 for Releuko.
How many units should be reported?
Each unit represents 1 microgram. Divide the administered filgrastim-sndz dose in micrograms by 1 to determine the drug units.
What should documentation identify?
Document the Zarxio product administered and the dose in micrograms; each microgram supports one Q5101 unit.
How does Medicare treat Q5101?
CMS excludes Q5101 from the physician fee schedule with status E. When Medicare covers the drug, it is paid under another method; CMS identifies it as a Part B drug generally priced through quarterly ASP files and assigns special coverage instructions.
Is Q5101 interchangeable for billing with pegfilgrastim codes?
No. Q5101 represents filgrastim-sndz per microgram; pegfilgrastim products have separate codes and dosing units.
Where these rates come from
FeeBase calculates base physician payments from CMS work, practice-expense and malpractice RVUs, adjusted by each locality’s geographic indexes and the conversion factor. Services without a published rate are labeled, never given a made-up amount. Amounts are Medicare allowed amounts before claim adjustments: not a patient’s bill or a commercial rate.
CMS RVU26D · effective Oct 1, 2026 through the day before Jan 1, 2027
Fee sheets · Coming soon
Put Q5101 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Join the waitlist