Retacrit (epoetin alfa-epbx) — HCPCS Q5106 & Q5105

Q5106 vs Q5105 — code selection by indication CMS HCPCS verified May 2026

Retacrit is one drug with two HCPCS codes. Code selection depends on dialysis status, not dose.

When CMS established permanent biosimilar HCPCS codes for Retacrit on July 1, 2018, it followed the existing reference-product convention of separating ESA billing into two distinct codes — one for ESRD patients on dialysis (which is bundled into the ESRD PPS) and one for all other uses. Same drug, same NDCs, same vials — but two HCPCS codes with two different unit bases.

Unit-basis trap — 1,000 IU vs 100 IU CMS HCPCS verified May 2026

The single highest-frequency biller error on Retacrit. Document this in your shop's quick-reference card.

Q5106 and Q5105 represent the same molecule at the same per-IU cost — but the unit bases differ by a factor of 10. A clinician orders "10,000 IU SC weekly" and that order maps to 10 units of Q5106 (10,000 / 1,000) for a chemo patient or 100 units of Q5105 (10,000 / 100) for an HD patient. Same dose, 10x different units billed.

Dosing & unit math FDA label verified May 2026

From FDA prescribing information, BLA 125545 (Retacrit).

CKD anemia (NDD-CKD or ESRD on dialysis)

• Initial: 50–100 IU/kg three times weekly (IV for HD; SC for NDD-CKD/PD)
• Goal: Hgb 10–11 g/dL (KDIGO target). Do not aim for normal Hgb — class boxed warning applies.
• Iron repletion required: ferritin > 100 ng/mL and TSAT > 20% before initiating.
• Titrate every 4 weeks. Hold for Hgb > 11 g/dL.

Chemo-induced anemia (non-myeloid malignancy)

• Option A: 150 IU/kg SC three times weekly
• Option B: 40,000 IU SC weekly (most common in practice)
• Initiation threshold: Hgb < 10 g/dL with at least 2 additional months of chemo planned
• Discontinue at chemo course completion. ESA APPRISE REMS acknowledgment required.

Zidovudine-treated HIV anemia

• 100 IU/kg SC or IV three times weekly
• Titrate up to 300 IU/kg three times weekly per response

Perioperative use (elective, non-cardiac, non-vascular surgery)

• 300 IU/kg/day SC for 10 days before surgery, day of surgery, and 4 days after surgery
• OR 600 IU/kg SC weekly × 3 doses (day -21, -14, -7) plus dose on day of surgery
• Concurrent DVT prophylaxis required

Worked example — 40,000 IU SC weekly chemo patient (Q5106)

NDC reference FDA NDC Directory verified May 2026

Retacrit vial sizes match Epogen/Procrit volumes. Verify the package NDC at billing time.

ESA class comparison — biosimilar cost advantage CMS Q2 2026

Retacrit was the first FDA biosimilar ESA. Cost advantage vs reference and long-acting agents drives biosimilar-preferred policy adoption.

Administration codes CPT verified May 2026

Retacrit is not a chemotherapy drug. Use therapeutic admin codes, not chemo admin codes.

Modifiers CMS verified May 2026

JZ — required on whole-vial single-dose claims with zero waste

Effective July 1, 2023, CMS requires the JZ modifier on all single-dose container claims when no drug is discarded. Retacrit vials are all single-dose. When the prescribed dose matches a vial size cleanly (e.g., 40,000 IU SC weekly using one 40,000 IU vial), bill JZ.

JW — reports discarded portion of single-dose vial

Many Retacrit doses do not match vial sizes cleanly. Example: a 70 kg CKD patient on 50 IU/kg three times weekly receives 3,500 IU per dose. From a 4,000 IU vial, 500 IU is discarded. Bill JZ on the administered units (3.5, rounded up to 4 if your MAC requires whole units) and JW on a separate line for the discarded units (1, representing 500 IU rounded). One of JZ or JW must appear on every Retacrit claim line with a single-dose vial.

Modifier 25 — same-day E/M

Use modifier 25 on the E/M code when a significant, separately identifiable evaluation and management service is performed on the same day as the Retacrit injection. Routine pre-injection clinical assessment is bundled into the admin code.

340B modifiers (JG, TB)

For 340B-acquired Retacrit, follow your MAC's current 340B modifier policy. JG was historically required for hospital outpatient 340B claims; TB applies to certain critical-access settings. Verify per-MAC policy at billing time.

ICD-10-CM by indication FY2026 verified May 2026

Anemia code plus underlying-cause code is required by all major payers and CMS LCDs.

Site of care & place of service Verified May 2026

Claim form field mapping Pfizer Encompass 2025

Boxed warning — ESA class warning FDA label verified May 2026

The boxed warning is a class warning — it applies identically to Retacrit (Q5106 / Q5105), Epogen/Procrit (J0885), Aranesp (J0881 / J0882), and Mircera (J0888). The biosimilar status of Retacrit does not change the safety profile or warning label.

Specific contraindications

• Uncontrolled hypertension
• Pure red cell aplasia (PRCA) following ESA therapy
• Serious allergic reaction to epoetin alfa or albumin

Hgb monitoring requirements

• Baseline Hgb before initiation (must be <10 g/dL for most indications)
• Weekly Hgb until stable, then monthly
• Hold dose if Hgb >11 g/dL (CKD) or >10 g/dL (cancer)
• Reduce dose 25% if Hgb increases >1 g/dL in any 2-week period

ESA APPRISE Oncology REMS FDA REMS verified May 2026

Required for ESA use in chemotherapy-induced anemia. Not required for CKD anemia.

The ESA APPRISE (Assisting Providers and cancer Patients with Risk Information for the Safe use of ESAs) Oncology Program is a class-wide REMS program covering all ESAs used in oncology — Retacrit, Epogen/Procrit, Aranesp, and Mircera. It is administered by the manufacturers in coordination with the FDA. The REMS is required for the chemo-induced anemia indication only; CKD anemia (NDD-CKD or ESRD) does not require ESA APPRISE enrollment.

REMS requirements for the chemo indication

• Prescriber enrollment in ESA APPRISE Oncology Program
• Hospital / institution enrollment for inpatient ESA use in cancer
• Patient acknowledgment form signed before each new chemotherapy course; documents the patient's understanding of risks (death, CV events, tumor progression)
• Prescriber-patient discussion documented in chart at initiation and at each chemo course
• REMS materials available at esa-apprise.com

Payer policy snapshot — biosimilar-preferred ESA Reviewed May 2026

UHC, Aetna, BCBS, and OptumRx 2024-2026 medical drug policies have shifted to biosimilar-preferred ESA. Reference J0885 typically requires step-edit override.

Medicare reimbursement CMS Q2 2026 (live)

Quarterly ASP from CMS Part B Drug Pricing File. Refreshes automatically each quarter.

Annual cost example — chemo patient on Retacrit

• 40,000 IU SC weekly × ~12 weeks of chemo = 12 doses
• 12 doses × 40 units × $7.883 = ~$3,784 drug cost (Medicare ASP+6%)
• After ~2% sequestration: ~$3,708 actual paid
• Plus admin (96372) per dose: ~$120–$180 for the course

Code history

• Q5106 — permanent code, effective July 1, 2018
• Q5105 — permanent code, effective July 1, 2018
• Pre-permanent-code period (May–June 2018): unclassified J3490 / J3590

Patient assistance — Pfizer Encompass Pfizer verified May 2026

• Pfizer Encompass: 1-844-989-7873 / pfizerencompass.com — benefits investigation, prior authorization assistance, appeal support, copay program enrollment
• Retacrit Co-pay Program: commercial copay support; eligible commercially-insured patients (excludes Medicare, Medicaid, federal program patients)
• Pfizer Patient Assistance Foundation: free product for uninsured / underinsured patients meeting income requirements
• Foundations for Medicare patients: PAN, HealthWell, CancerCare for chemo-induced anemia — verify open ESA / chemo support funds quarterly
• Web: pfizerencompass.com

Common denials & how to fix them

Frequently asked questions

What is the HCPCS code for Retacrit?

Retacrit (epoetin alfa-epbx) has TWO HCPCS codes for the same drug, distinguished by indication and unit basis. Q5106 — "Inj retacrit non-esrd use" — bills at 1,000 IU per unit and is used for all non-ESRD indications. Q5105 — "Inj retacrit esrd on dialysi" — bills at 100 IU per unit and is used only for ESRD patients on dialysis. Selecting the wrong code produces both denial and order-of-magnitude wrong dose math, because the unit bases differ by 10x.

How many units do I bill for a 10,000 IU Retacrit dose?

It depends on the code. For non-ESRD use under Q5106 (1,000 IU per unit): 10 units. For ESRD on dialysis under Q5105 (100 IU per unit): 100 units. Same drug, same dose, same vial — but a 10x difference in billed units depending on which HCPCS applies.

What administration CPT do I use for Retacrit?

For non-ESRD use (Q5106): CPT 96372 for therapeutic SC/IM injection (most common — Retacrit is typically given subcutaneously in CKD-NDD and chemo patients), or CPT 96365 for therapeutic IV infusion when given IV. For ESRD on dialysis (Q5105): the ESA is administered during the hemodialysis session and is bundled into the ESRD PPS bundled rate — no separate admin code is billed under the bundle.

What is the boxed warning for Retacrit?

Retacrit carries the same boxed warning as all ESAs: increased risk of death, serious cardiovascular events (myocardial infarction, stroke, venous thromboembolism), thromboembolism, and tumor progression or recurrence. Use the lowest dose sufficient to avoid red blood cell transfusion. For cancer patients, Retacrit is dispensed only under the ESA APPRISE Oncology REMS program. The boxed warning is class-wide and not specific to the biosimilar.

What is the Medicare reimbursement for Retacrit?

For Q2 2026, Q5106 (non-ESRD) ASP+6% is approximately $7.883 per 1,000 IU unit; Q5105 (ESRD on dialysis) ASP+6% is approximately $0.788 per 100 IU unit. Per-IU cost is identical — the same drug at the same per-IU price, just expressed against different unit bases. A 40,000 IU weekly chemo dose under Q5106 reimburses at approximately $315.32 per dose. ESRD on-dialysis ESA spend is folded into the bundled ESRD PPS payment.

Is Retacrit preferred over Epogen / Procrit?

Yes for many cost-conscious commercial and Medicare Advantage plans. Many UHC, Aetna, BCBS, and OptumRx 2024-2026 ESA medical-drug policies have shifted to biosimilar-preferred status, listing Retacrit (Q5106 / Q5105) ahead of reference Epogen/Procrit (J0885). Private-label ESA arrangements have emerged through CVS Cordavis, Express Scripts Quallent, and OptumRx Nuvaila that further lock in biosimilar economics.

What ICD-10 codes are used with Retacrit?

For NDD-CKD anemia: N18.3, N18.4, N18.5 paired with D63.1. For ESRD on dialysis: N18.6 paired with Z99.2 and D63.1. For chemo-induced anemia: D64.81 plus the underlying cancer code (non-myeloid only). For zidovudine-treated HIV: B20 plus D63.8. CMS LCDs also restrict Retacrit to Hgb thresholds — typically initiation below 10 g/dL with iron-replete documentation.

How do I select between Q5106 and Q5105 for the same patient?

Code selection follows dialysis status, not dose. Use Q5105 only when (a) ICD-10 N18.6 ESRD is documented, AND (b) the patient is on chronic maintenance hemodialysis or peritoneal dialysis, AND (c) the ESA is administered during dialysis. Use Q5106 for everyone else: NDD-CKD (N18.3-N18.5 not yet on dialysis), chemo patients, surgery patients, AKI on temporary dialysis, and HIV patients. Wrong selection produces both a denial and a 10x miscalculation of billed units.

Source documents

1. Pfizer Encompass — Retacrit access program
   Patient assistance + benefits investigation + 1-844-989-7873
2. DailyMed — RETACRIT (epoetin alfa-epbx) Prescribing Information
   FDA-approved label, BLA 125545, first FDA biosimilar ESA (May 15, 2018)
3. FDA Biosimilar Product Information — Retacrit
   FDA biosimilar approval and licensure information
4. CMS — Medicare Part B Drug ASP Pricing File
   Q2 2026 quarterly file; Q5106 + Q5105 separate ASP entries
5. CMS — ESRD Prospective Payment System
   Bundling structure for ESRD-on-dialysis ESA payment under Q5105
6. ESA APPRISE Oncology Program — class-wide REMS
   Class REMS for ESA use in chemo-induced anemia
7. KDIGO Guideline — Anemia in CKD
   Hgb 10-11 g/dL target; iron-repletion criteria
8. UnitedHealthcare — ESA medical drug policy (biosimilar preferred)
9. Aetna — ESA Clinical Policy Bulletin
10. CMS Medicare Coverage Database — ESA LCDs (per-MAC)
    Hgb threshold + iron-replete + REMS criteria
11. FDA National Drug Code Directory — Retacrit NDCs

About this page

We maintain this page as a living reference. Medicare ASP pricing is bound to our underlying CareCost data layer and refreshes automatically when CMS publishes new quarterly files. Coding and policy content is reviewed at least quarterly and updated whenever a source document changes.

Found an error? Email hello@carecostestimate.com.

Refresh cadence

Reviewer

Change log

• May 2, 2026 — Initial publication. ASP data: Q2 2026 (Q5106 = $7.883/unit, Q5105 = $0.788/unit). Manufacturer: Pfizer Encompass 2025. FDA label: BLA 125545, first FDA biosimilar ESA (May 15, 2018). Both Q5106 and Q5105 documented with unit-basis trap call-outs.

Methodology

Every claim on this page is sourced inline. Pricing reflects the current CMS Part B Drug ASP Pricing File for both Q5106 and Q5105. Payer policies are read directly from each payer's published medical drug policy documents. ESA APPRISE REMS requirements are from the program's official site. Hgb / iron-replete thresholds are read from CMS MAC LCDs and KDIGO. We do not paraphrase from billing-software vendor blogs.