HCPCS Code Q5103: Injection, infliximab-dyyb, biosimilar (Inflectra®), 10 mg

Maximize reimbursement for HCPCS Q5103. Our guide covers documentation and billing for Inflectra® to ensure accurate claims.

Use Code

## **What is infliximab-dyyb (Inflectra®)?** HCPCS code Q5103 describes an injection of infliximab-dyyb, a biosimilar, 10 mg. Inflectra® is a biosimilar to infliximab (Remicade®), a chimeric monoclonal antibody that inhibits tumor necrosis factor-alpha (TNF-α). It is used in the treatment of autoimmune conditions such as rheumatoid arthritis, Crohn’s disease, ulcerative colitis, ankylosing spondylitis, psoriatic arthritis, plaque psoriasis, and other indications such as Behçet’s disease and graft-versus-host disease. Like the reference product, Inflectra® is administered by intravenous infusion in a clinical setting, not self-administered. Dosing is weight-based, with induction therapy initiated prior to maintenance infusions. Clinicians often track swollen joint count, tender joint count, abdominal pain, and rheumatoid factor to assess therapeutic response. Patients must be closely monitored for adverse outcomes, including infusion reactions, infections, and potential worsening of heart failure.

## **Q5103 documentation requirements** Clear, complete records establish medical necessity and prevent denials. ### **Prescription and diagnosis** Maintain a valid signed order or Standard Written Order (SWO) that specifies Inflectra®, the total dose, frequency, and route of administration. Link the order to an FDA-approved indication such as Crohn’s disease, rheumatoid arthritis, or other covered conditions documented by the Centers for Medicare & Medicaid Services (CMS). ### **Dose and infusion details** Document the total milligrams infused, the number of HCPCS billing units (per 10 mg), and any discarded drug. Infusion start/stop times, infusion rate, and premedications must also be recorded. ### **Product identification** Include the lot number, vial size, and NDC of the product supplied. This ensures traceability and supports payer and coding information requirements. ### **Medical necessity and continuation** Describe the clinical rationale for initiating therapy and continuation, particularly when patients show inadequate response to other treatments. Progress notes should reflect improvement in disease activity measures (e.g., joint counts, GI symptoms) and ongoing benefit.

## **Q5103 billing requirements** Submit claims that match the chart and follow payer policy. ### **Billing units** Bill Q5103 per 10 mg. For example, a 400 mg infusion equals 40 units. Ensure the claim reflects the actual administered dose. ### **Waste reporting** If part of a vial is discarded, report the JW modifier for wasted drug and the JZ modifier if no drug was wasted. Record wastage in the medical record. ### **Product specificity** Do not bill Q5103 for Remicade® or other infliximab biosimilars. Use the HCPCS code that matches the exact product infused. ### **Medicare and payer review** Medicare Administrative Contractors (MACs) and other payers may review infusion claims and request infusion logs, prescriptions, and clinical notes. Medicare reimburses biosimilars like Inflectra® based on average sales price (ASP) plus 6% of the reference biologic. Thorough documentation helps reduce the risk of denials (Centers for Medicare & Medicaid Services, 2022).

## **Q5103 applicable modifiers** Use these modifiers when billing Q5103: - **JW** – Drug amount discarded/not administered - **JZ** – Zero drug wasted - **KX** – Requirements specified in the medical policy have been met Modifier for manufacturer/payer requirement – Some payers require manufacturer-specific identifiers for biosimilars

## **References** Centers for Medicare & Medicaid Services. (2022). Frequently asked questions inflation reduction act biosimilars temporary payment increase. https://www.cms.gov/files/document/biosimilar-faqs.pdf

Frequently asked questions

You should bill 40 units of Q5103, since each unit equals 10 mg. Always confirm that the billed amount matches the documented infusion dose in the medical record.

No. As of April 1, 2018, CMS discontinued the requirement for manufacturer-specific modifiers (such as ZB). You only need to report Q5103 for Inflectra® along with the correct NDC and number of units.

No. J1745 is specific to Remicade® (the reference product), while Q5103 is for Inflectra®. Claims must reflect the exact product administered to avoid denials.