HCPCS Code Q0138: Ferumoxytol injection billing guide (non-ESRD)

Key Takeaways

HCPCS Code Q0138 covers injection, ferumoxytol (Feraheme), for treatment of iron deficiency anemia, billed per 1 mg for non-ESRD patients.

Feraheme is supplied as a 510 mg/17 mL single-dose vial (NDC 59338-0775-xx), so one vial equals 510 billable units under Q0138.

CMS classifies Q0138 as a single-dose container, making JW and JZ wastage modifiers mandatory when any portion of the vial is discarded or fully used.

Pabau’s claims management software supports buy-and-bill drug billing workflows, helping infusion centers track Q0138 units, modifiers, and documentation in one place.

Iron deficiency anemia affects millions of patients who cannot tolerate or absorb oral iron supplements, and intravenous ferumoxytol has become a widely used treatment. Getting the billing right matters: a single 510 mg Feraheme vial billed under the wrong code, or without the correct wastage modifier, can trigger a claim denial or a compliance audit. This guide covers HCPCS Code Q0138, including its code description, the Q0138 vs Q0139 distinction, NDC crosswalk, JW/JZ modifier requirements, Medicare reimbursement, and the documentation coders and infusion center staff need to support clean claims.

HCPCS Code Q0138: Clinical description and code properties

HCPCS Code Q0138 is the correct billing code when ferumoxytol (brand name Feraheme) is given to a patient with iron deficiency anemia who does not have end-stage renal disease (ESRD) and is not on dialysis. The official CMS descriptor reads: Injection, ferumoxytol, for treatment of iron deficiency anemia, 1 mg (non-ESRD use).

Q-codes fall under HCPCS Level II, which CMS maintains as the standard coding system for drugs, supplies, and services not covered by CPT. The coverage indicator “carrier judgment” means that local Medicare Administrative Contractors (MACs) determine medical necessity on a case-by-case basis, and coverage decisions may vary by region. Providers billing to commercial payers should verify whether payers require prior authorization before you administer the drug.

Feraheme got its original FDA approval in 2009 for iron deficiency anemia in adults with chronic kidney disease. In 2018, the FDA expanded its indication to all adult patients with iron deficiency anemia who have had an inadequate response or intolerance to oral iron. Providers can bill Q0138 for this broader population, but coders must still document the specific indication to support medical necessity review.

Q0138 vs Q0139: Choosing the correct ferumoxytol code

Selecting the wrong code between Q0138 and Q0139 is one of the most common denial triggers for ferumoxytol claims. The distinction is straightforward but critical: patient ESRD and dialysis status determines which code applies.

• Q0138: Ferumoxytol injection, 1 mg, for non-ESRD patients (patients not on dialysis)
• Q0139: Ferumoxytol injection, 1 mg, for ESRD patients on dialysis

Both codes are billed per 1 mg and share the same NDC. The reimbursement methodology differs because Medicare pays for ESRD-related drugs under the ESRD bundled payment system (Medicare Part B ESRD bundle) rather than the standard Average Sales Price (ASP) + 6% method used for Q0138. Billing Q0138 for a dialysis patient, or Q0139 for a non-dialysis patient, will result in a claim denial. Verify the patient’s ESRD status in their record before selecting the code, and document this clearly in the chart note.

For outpatient infusion centers treating patients with IV therapy EMR software, maintaining an accurate, up-to-date problem list that flags ESRD status makes this distinction automatic at the point of care rather than a post-service reconciliation step.

NDC crosswalk and vial specifications

When billing Q0138 to Medicare and many commercial payers, providers must also report the National Drug Code (NDC) on the claim. Feraheme is manufactured by Covis Pharma (formerly AMAG Pharmaceuticals) and is commercially available in a single formulation.

The “xx” suffix in the NDC represents the package configuration code, which varies by distributor. When submitting the NDC on a CMS-1500 or UB-04 claim, use the 11-digit format with leading zeros (5-4-2 configuration: 59338-0775-01 as an example). Report the quantity in metric units (milligrams) alongside the NDC, and verify the NDC qualifier code is “UN” (units) when applicable.

Most infusion centers purchase Feraheme through a specialty distributor under the buy-and-bill model. The practice acquires the drug, administers it, and then bills the payer directly for the drug cost (Q0138 units) plus the infusion administration code (typically CPT 96365 for the initial hour and 96366 for additional hours). Keeping pharmacy acquisition records aligned with billing records is essential for audits. An EMR built for IV therapy can link drug lot numbers and purchase records directly to patient encounter documentation, simplifying this review.

JW and JZ wastage modifiers for Q0138

CMS has designated Feraheme (Q0138) as a single-dose container drug, which means JW and JZ wastage modifiers apply. This policy took effect January 1, 2023 and applies to all Part B drug claims for single-dose vials.

How JW and JZ work for Q0138

• JW modifier (drug wastage): Append JW to a separate line on the claim when a portion of the single-dose vial was discarded and not administered to the patient. Bill the administered dose on one line (Q0138 x units administered) and the wasted amount on a second line (Q0138 x units discarded + JW). This allows Medicare to reimburse the full vial cost while separately tracking waste.
• JZ modifier (no drug wastage): Append JZ to the claim line when the entire vial content was administered to the patient and no drug was discarded. One line: Q0138 x 510 units + JZ modifier.

Failure to append either JW or JZ when billing Q0138 under Medicare Part B will result in a claim rejection or edit flag. Coders should confirm the administered dose with the administering nurse or infusion pharmacist before submitting. Standard Feraheme dosing is either 510 mg (one full vial) or 1,020 mg (two sequential infusions), but actual administered amounts may vary based on clinical protocol.

For Correct Coding Initiative (CCI) purposes, Q0138 does not have known CCI bundling edits that prevent billing alongside infusion administration CPT codes. However, MAC-specific Local Coverage Determinations (LCDs) may impose additional billing rules, so always check the applicable MAC policy for the service jurisdiction.

Medicare reimbursement and fee schedule

Medicare Part B reimburses Q0138 under the ASP methodology: ASP plus 6% of the drug’s average sales price. Because ferumoxytol is billed per 1 mg and a standard 510 mg vial is administered as a single dose, reimbursement is calculated by multiplying the per-mg ASP rate by 510 units. CMS publishes ASP rates quarterly and are subject to change each January, April, July, and October.

Use the CMS Physician Fee Schedule lookup tool to find the current ASP payment limit for Q0138 for your MAC locality. Note that Feraheme is a relatively high-cost iron therapy compared to alternatives like iron sucrose (Venofer) or ferric carboxymaltose (Injectafer), so prior authorization requirements from commercial payers are common. Medicare describes coverage as ‘carrier judgment’, meaning reimbursement is not guaranteed without proper medical necessity documentation.

In addition to the drug cost (Q0138), facilities may separately bill for infusion administration. Hospital outpatient departments and ASC-affiliated infusion centers typically use APC (Ambulatory Payment Classification) rates rather than the Physician Fee Schedule. Independent physician-owned infusion centers bill under the standard MPFS. Confirm the correct payment system with your compliance officer before coding multi-site Q0138 services.

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Medical necessity criteria and documentation requirements

Because Q0138 coverage is “carrier judgment,” strong documentation is the primary defense against denials. Payers reviewing ferumoxytol claims typically look for evidence that oral iron was tried first and failed, or that the patient has a contraindication to oral iron. Following IV therapy clinic best practices on documentation reduces denial rates significantly.

Documentation checklist for Q0138 claims

• Diagnosis code for iron deficiency anemia (ICD-10-CM D50.9 or the specific anemia code) clearly linked to the Q0138 line
• Confirmation that the patient does NOT have ESRD and is not on dialysis (supporting Q0138 rather than Q0139)
• Trial and failure of oral iron supplementation, or documented contraindication or intolerance
• Pre-treatment hemoglobin and ferritin/transferrin saturation lab values from within 30-90 days (payer-specific windows apply)
• Prescribing clinician’s order for ferumoxytol, including dose and indication
• Infusion administration record showing the actual milligrams administered (drives JW/JZ modifier selection)
• NDC reported on the claim with quantity in milligrams

Structured digital intake forms that capture hemoglobin values, prior oral iron trial history, and ESRD status at the point of consent remove documentation gaps before the infusion occurs. When the clinical record is complete at the time of service, coders have everything they need without chasing physicians for addenda.

For practices opening an IV therapy clinic that plans to administer Feraheme, building these documentation requirements into the intake workflow from day one prevents the back-office scramble that leads to late filing and avoidable write-offs. Pabau’s claims management software connects intake form data to billing workflows, so the documentation that supports Q0138 medical necessity is already attached to the claim before it leaves the practice.

Billing workflow: Step-by-step for Q0138

Infusion centers that bill Q0138 regularly benefit from a standardized workflow that reduces errors at each stage. Here is a condensed step-by-step process for clean Q0138 claims.

1. Verify ESRD status and indication. Before the appointment, confirm the patient’s ESRD status in the chart. Non-ESRD = Q0138. ESRD on dialysis = Q0139. Document this determination.
2. Confirm prior authorization. Check payer requirements. Commercial payers often require prior auth for Feraheme. Medicare doesn’t, but requires medical necessity documentation. If needed, obtain authorization before infusion and include the reference number on the claim.
3. Record the administered dose. The nursing or infusion record must document the exact milligrams administered from the vial. This drives your billing units (quantity = mg administered) and determines whether JW or JZ applies.
4. Select the correct modifier. If the full 510 mg vial was administered: Q0138 x 510 units + JZ. If a partial dose was administered (e.g. 500 mg): Q0138 x 500 units administered + Q0138 x 10 units discarded + JW modifier on the waste line.
5. Report the NDC. Include NDC 59338-0775-xx with the 11-digit format, qualifier “UN,” and quantity in milligrams on the same claim line as Q0138.
6. Code the infusion administration. Bill CPT 96365 for the initial 15 minutes to 1 hour of intravenous infusion, plus 96366 for each additional hour, and are reported separately from Q0138.
7. Attach supporting documentation. Ensure the claim or accompanying records include the lab values, diagnosis codes, and prescriber order that support medical necessity.

Review the AAPC’s HCPCS code reference to cross-check Q0138 properties before submitting, and use the PGM Billing HCPCS lookup tool for a quick free check of the code’s current billing properties. For IV therapy intake form templates that capture the clinical data required for Q0138 claims, a pre-built form cuts documentation time per infusion significantly.

Common denial reasons and how to appeal Q0138 claims

Ferumoxytol claims are denied for predictable reasons. Recognizing these patterns early makes appeals faster and prevents repeat errors.

• Missing or incorrect wastage modifier. The most common denial since CMS’s January 2023 mandate. Append JW or JZ on every Q0138 Medicare claim. Appeal with the corrected claim and a copy of the infusion administration record.
• Wrong code: Q0138 billed for dialysis patient. Payers cross-check Q0138 against ESRD enrollment data. If a patient’s record shows ESRD, the claim will reject. Appeal requires documentation that the patient was not on dialysis at the time of service, or rebill as Q0139 if they were.
• Missing NDC. Many payers require the NDC on drug claims. If omitted, correct and resubmit with the full 11-digit NDC and metric quantity.
• Medical necessity not established. Carrier judgment denials require an appeal with clinical documentation: diagnosis, lab values, and trial of oral iron. Submit a letter of medical necessity from the treating physician with the redetermination request.
• Units billed exceed vial size. Billing more than 510 units for a single Feraheme vial will trigger an edit. Verify that billed units match the administered dose plus any JW waste line, totaling no more than 510 per vial.

You can correct most Q0138 denials on first appeal when the supporting documentation is already in the patient record. The key is having that documentation complete before the claim is initially submitted rather than gathering it after a denial arrives.

Conclusion

HCPCS Code Q0138 billing hinges on three things done correctly every time: the right code for the patient’s ESRD status, the correct JW or JZ modifier on every single-dose vial claim, and documentation that establishes medical necessity before the claim goes out. When those elements are in place, Q0138 claims clear at a high rate and appeals are rarely needed.

Pabau’s claims management software connects intake documentation, drug administration records, and billing workflows so the evidence supporting each Q0138 claim is already attached when it reaches the payer. To see how Pabau handles infusion billing workflows end to end, book a demo.

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