HCPCS code J1441: Filgrastim (G-CSF) 480 mcg injection guide

Key Takeaways

HCPCS code J1441 described a flat 480 mcg dose of filgrastim (G-CSF) and is no longer in the active HCPCS Level II code set.

CMS deleted J1441 effective January 1, 2014, so December 31, 2013 was the last valid date of service for the code.

J1442 (filgrastim, excludes biosimilars, 1 microgram) is the active replacement, billed as 480 units for a 480 mcg dose.

J1440 is not the replacement. It was deleted in the same 2014 action, and CMS reassigned the number to Rebyota.

Biosimilar filgrastim carries product-specific codes, including Q5101 for Zarxio and Q5110 for Nivestym. J3262 is tocilizumab, not filgrastim.

Practice management software like Pabau flags retired codes before submission and keeps drug administration records attached to the claim.

HCPCS code J1441 described an injection of filgrastim (granulocyte colony-stimulating factor, G-CSF) at a flat dose of 480 mcg. Filgrastim stimulates neutrophil production in patients receiving chemotherapy, undergoing bone marrow transplant, or living with severe chronic neutropenia. Neupogen (Amgen) was the originator brand billed under this code.

The code is no longer valid. CMS deleted J1441 effective January 1, 2014, in the annual HCPCS Level II update. Its sister flat-dose code J1440 (300 mcg) was retired in the same action, and one per-microgram code, J1442, replaced both.

The old J1440 number is in use again, but CMS reassigned it to an unrelated product, Rebyota (fecal microbiota, live-jslm). A filgrastim claim submitted under J1440 today reports the wrong drug. This reference covers what J1441 held, when it died, the crosswalk to active codes, and how to bill filgrastim now.

J1441 code details at a glance

The table below lists the reference data for HCPCS code J1441 (Injection, filgrastim (G-CSF), 480 mcg). It is what you need when auditing historical claims or answering a payer query about a pre-2014 encounter. For current billing, use the crosswalk in the next section.

Is J1441 still active? Code status and deletion history

HCPCS code J1441 is not active. CMS deleted it effective January 1, 2014, in the annual HCPCS Level II update announced in late 2013. December 31, 2013 was the last date of service the code could cover.

The change was about billing units rather than coverage. Both flat-dose filgrastim codes went at once, J1440 for 300 mcg and J1441 for 480 mcg. CMS replaced them with J1442, which bills per 1 microgram, so the claim carries the dose actually administered instead of a vial size.

A second deletion date circulates online. Several billing write-ups place the removal of J1441 in a mid-year 2019 HCPCS update, and no mid-year 2019 update touched this code. The only CMS document that names J1440 and J1441 together is program memorandum A02050. It was published in 2002 and listed co-pay amounts while both codes were still active.

If J1441 still sits in your charge master, filgrastim claims will not reach adjudication. Clearinghouses reject codes that are absent from the active CMS HCPCS file, so the claim never becomes a payer denial. Rejections like these never enter the denial queue, which is how a code retired in 2014 can keep failing quietly for months.

Revenue cycle teams should re-audit the charge master at every quarterly HCPCS update. That catches deletions before they reach a claim, and it catches reassigned numbers like J1440 before they reach the wrong drug.

What code replaced J1441? Crosswalk to active codes

J1442 replaced HCPCS code J1441. Its descriptor is injection, filgrastim (G-CSF), excludes biosimilars, 1 microgram, so the quantity field carries the micrograms given. A 480 mcg Neupogen dose is billed as J1442 with 480 units.

Do not reach for J1440 as the replacement. That code was deleted alongside J1441 in 2014, and CMS has since reassigned the number to Rebyota (fecal microbiota, live-jslm, 1 ml). A filgrastim claim submitted under J1440 now reports a Clostridioides difficile therapy instead.

The table below maps J1441 to the codes in use today. Verify each entry against the CMS HCPCS overview and the current annual code file before a billing cycle.

One crosswalk error is worth naming, because it appears in several billing articles. J3262 is not a filgrastim code and is not assigned to Nivestym. J3262 describes injection, tocilizumab, 1 mg, the rheumatoid arthritis biologic sold as Actemra. Nivestym (filgrastim-aafi) is billed under Q5110.

For unit calculation, place-of-service rules, and the ICD-10 pairings that support medical necessity under the replacement code, see our reference on HCPCS code J1442. The AAPC HCPCS code lookup and the PGM Billing HCPCS search tool both show current status alongside historical records.

J1442 vs J1441: what changed for billers

Both codes covered originator filgrastim, and the billing unit is the whole difference. J1441 billed a fixed 480 mcg dose as a single unit. J1442 bills per microgram, so the biller reports the actual micrograms administered as the quantity.

The migration error to watch for is a quantity of 1. Setting up J1442 with one unit bills 1 mcg instead of 480 mcg, which underpays the claim by a factor of 480. When you build the charge for a 480 mcg vial, the quantity must equal the total micrograms administered.

Write that logic into the charge entry workflow rather than leaving it to memory. Practices managing mobile IV therapy and injectable drug billing face the same quantity-entry risk across every per-microgram J-code they touch.

Filgrastim biosimilar HCPCS codes

Biosimilar filgrastim reached the US market in 2015 with Zarxio (filgrastim-sndz), and CMS assigns each product its own HCPCS code. Billing the originator code for a biosimilar, or the reverse, creates a drug-to-code mismatch. That mismatch can fail the NDC crosswalk or pull the claim into medical review.

Practices billing IV therapy and injectable biologics need to match the dispensed product to its own code. The current filgrastim family looks like this:

• J1442 – Injection, filgrastim (G-CSF), excludes biosimilars, 1 microgram. The originator code, used for Neupogen (Amgen) only.
• Q5101 – Injection, filgrastim-sndz (Zarxio), biosimilar, 1 microgram. Zarxio was the first biosimilar G-CSF approved in the US.
• Q5110 – Injection, filgrastim-aafi (Nivestym), biosimilar, 1 microgram. Nivestym came from Pfizer and Hospira in 2018.
• Q5125 – Injection, filgrastim-ayow (Releuko), biosimilar, 1 microgram. Releuko comes from Amneal Pharmaceuticals and Kashiv BioSciences.
• Q5148 – Injection, filgrastim-txid (Nypozi), biosimilar, 1 microgram. Nypozi is the Tanvex BioPharma product.
• J1447 – Injection, tbo-filgrastim, 1 microgram. Granix (Teva) carries its own code and is never billed under J1442.

Every code in that list bills per 1 microgram, so the quantity logic is identical across products. Only the code changes when the dispensed product changes. Cross-reference the product NDC against the CMS Physician Fee Schedule lookup before each billing run to confirm the crosswalk is current.

Medicare and payer coverage for filgrastim

Medicare Part B covers filgrastim injections administered incident-to in a physician office or outpatient setting, provided the clinical indication is documented. Covered indications commonly include chemotherapy-induced neutropenia, bone marrow transplant support, and severe chronic neutropenia. Coverage is not automatic, and the medical necessity record has to support the claim.

CMS program memorandum A02050, issued in 2002, listed Medicare co-pay amounts for J1440 and J1441 while both codes were active. Those figures are more than two decades old and say nothing about current payment. Part B pays injectable drugs at average sales price (ASP) plus 6%, and CMS republishes those rates quarterly.

Pull current rates from the CMS Physician Fee Schedule or from your Medicare Administrative Contractor (MAC) fee schedule, never from an archived transmittal. Commercial payer policy varies. Most follow the Medicare medical necessity framework, and some require prior authorization for outpatient self-administered doses.

HIPAA-compliant documentation of the clinical indication is needed for every payer, with or without prior authorization. Practices using injectable therapy intake and documentation should capture that indication in structured fields tied to the billing record.

Documentation requirements for filgrastim claims

A filgrastim claim needs a record that ties the drug to the encounter, the indication, and the exact dose given. Missing any one of those links gives a payer clean grounds to deny on medical necessity or documentation. Keep this minimum set on file for every administration.

• Physician order: dated and signed, naming the drug, dose, route, and frequency.
• Supporting diagnosis: the ICD-10 code documented in the encounter note and linked on the claim.
• Administration record: date, time, product name, NDC, lot number, micrograms administered, and route.
• Lab results: the absolute neutrophil count supporting the neutropenia or prophylaxis indication.
• Prior authorization: the payer reference number, approval dates, and authorized quantity, where required.
• Waste documentation: the amount discarded when only part of a vial is used, per payer rules.

Defending a pre-2014 encounter runs on the same record set plus one extra item. Keep the code set that was active on the date of service alongside the original claim. The reviewer can then see that J1441 was valid when it was billed.

How to bill filgrastim injections correctly today

With J1441 retired, the workflow below is the current path for a filgrastim claim. Following it reduces clearinghouse rejections and protects against NDC-to-HCPCS crosswalk failures.

1. Confirm the dispensed product. Identify whether the patient received originator filgrastim (Neupogen) or a biosimilar such as Zarxio, Nivestym, Releuko, or Nypozi. The code follows the specific product, not the drug class.
2. Select the correct HCPCS code. Use J1442 for Neupogen, Q5101 for Zarxio, Q5110 for Nivestym, Q5125 for Releuko, or Q5148 for Nypozi. Neither J1440 nor J1441 belongs on a filgrastim claim.
3. Set the quantity correctly. Every current filgrastim code bills per 1 microgram, so enter the total micrograms administered. A standard 480 mcg Neupogen dose is J1442 x 480 units.
4. Report the NDC. Medicare and many commercial payers require the 11-digit National Drug Code for physician-administered drugs. Take the NDC from the product label, not from a crosswalk assumption.
5. Document medical necessity. Record the clinical indication in the patient chart. For Medicare, that means a diagnosis code mapping to a covered filgrastim indication, such as chemotherapy-induced neutropenia.
6. Submit the administration code separately. The J-code pays for the drug. The injection itself is billed under the appropriate CPT administration code, typically 96401 or 96372 depending on route and clinical context.

Practices with EMR systems built for IV therapy and injectable drug workflows can automate parts of this. NDC capture at the point of administration and a validation rule that rejects J1441 at charge entry are the two highest-value pieces. Catching the code inside the practice costs far less than working the rejection afterwards.

For practices opening an IV therapy clinic or adding injectable services, build the J-code logic correctly on day one. That beats correcting a year of underbilled claims.

NDC codes associated with J1441

While J1441 was active, its associated NDCs corresponded to Neupogen vial presentations manufactured by Amgen. An NDC is an 11-digit identifier assigned by the FDA. It appears on the drug label as labeler code, product code, and package code segments.

For an audit or appeal covering a pre-2014 encounter, use the NDC-to-HCPCS crosswalk file for that date of service. CMS publishes historical crosswalk files by effective date on the CMS HCPCS page, mapping each NDC to the code that was active at the time.

Do not apply a current-year crosswalk file to a 2013 claim, because the flat-dose codes were still valid then. A versioned archive of crosswalk files makes those audit responses considerably faster to assemble.

How Pabau keeps retired J-codes off your claims

Most J-code failures start in the charge master. A retired code such as J1441 stays in place until someone traces the rejections back to it. Quantity logic built for a flat dose keeps underbilling in the meantime.

Practice management software like Pabau keeps the clinical record and the claim in one system. The product, NDC, lot number, and micrograms administered are recorded at the point of care and carried into the charge. Billing staff work from the administration record instead of re-entering it.

Pabau’s claims management software validates charges before they leave the practice. A legacy code or a quantity of 1 surfaces internally rather than at the clearinghouse. Prescription management software handles the structured drug recording behind it, and EHR integration removes the manual re-entry that produces quantity errors.

Catch retired J-codes before the claim goes out

Pabau keeps drug administration records, NDC data, and diagnosis codes on one patient file. Charge validation runs before submission, so filgrastim claims leave your practice clean.

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Conclusion

HCPCS code J1441 has been invalid since January 1, 2014, and any charge master still carrying it is generating rejections on filgrastim claims. The fix is a code swap plus a quantity change. Bill J1442 for originator filgrastim at one unit per microgram, and use the product-specific Q code for each biosimilar.

Two traps sit around that swap. J1440 is not the replacement, because CMS reassigned that number to Rebyota. J3262 is not Nivestym either, since it describes tocilizumab. Nivestym belongs to Q5110.

For practices billing injectable drugs at volume, Pabau’s claims management software flags legacy codes before submission and keeps administration documentation attached to the claim. See how that works by booking a demo at pabau.com/book-demo.

Continue your research

Need to manage injectable drug billing across multiple clinic locations? IV therapy EMR software features covers how Pabau structures drug administration records and charge entry for injectable therapy clinics.

Want a framework for setting up compliant IV therapy intake documentation? IV therapy intake form guide walks through the clinical and billing data fields that support accurate J-code claims.

Looking to understand how EMR integration reduces injectable drug billing errors? EHR integration for clinics explains how connected clinical and billing workflows reduce quantity-entry errors on drug claims.

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