HCPCS code Q5114: Billing guide for trastuzumab-dkst (Ogivri)

Key Takeaways

HCPCS code Q5114 describes Injection, trastuzumab-dkst, biosimilar, (Ogivri), 10 mg – a HER2-targeted biosimilar billed per 10 mg unit via intravenous infusion.

Q5114 is FDA-approved for HER2-overexpressing breast cancer and HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma.

Medicare Part B covers Q5114 under buy-and-bill with ASP+6% reimbursement – rates change quarterly, so verify the current figure against the CMS ASP Drug Pricing file.

Pabau’s claims management software helps practices track claim status, documentation, and payer requirements in one place.

HCPCS code Q5114: Definition

HCPCS code Q5114 covers Injection, trastuzumab-dkst, biosimilar, (Ogivri), 10 mg — a HER2-targeted biosimilar administered by IV infusion and billed per 10 mg unit. The code applies to one specific product, dosed in 10 mg units, for a defined set of FDA-approved diagnoses.

Q5114 is the CMS-assigned HCPCS Level II Q-code for the drug, reported on Medicare, Medicaid, and commercial payer claims whenever Ogivri is administered by infusion. This reference covers the full billing picture: code details, FDA-approved indications, billing unit rules, the ICD-10 crosswalk, Medicare reimbursement methodology, and related biosimilar codes.

Code description and details

The full descriptor for Q5114 is: Injection, trastuzumab-dkst, biosimilar, (Ogivri), 10 mg. Trastuzumab-dkst is the INN (International Nonproprietary Name) for the active ingredient. Ogivri is the brand name, manufactured by Biocon Biologics.

Q-codes are temporary national codes maintained by CMS. They are commonly used for biologics and biosimilars while a permanent J-code assignment is pending or under review. Always confirm the code remains active against the current annual update from the CMS HCPCS code list.

FDA-approved indications for Ogivri (trastuzumab-dkst)

Q5114 may only be billed for FDA-approved indications. Submitting a claim for an off-label use without supporting MAC LCD coverage is a compliance risk. Ogivri carries the same FDA-approved indications as its reference product, Herceptin.

• HER2-overexpressing breast cancer (adjuvant): Ogivri is indicated as part of a treatment regimen for early-stage HER2-overexpressing breast cancer following surgery, chemotherapy, and radiation. This is the most common billing scenario for Q5114.
• HER2-overexpressing metastatic breast cancer: Indicated as first-line therapy in combination with paclitaxel, or as monotherapy in patients who have received prior chemotherapy for metastatic disease.
• HER2-overexpressing metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma: Indicated in combination with cisplatin and a fluoropyrimidine for patients who have not received prior treatment for metastatic disease.

Off-label trastuzumab-dkst use may be covered under specific MAC Local Coverage Determinations (LCDs), but coverage is not universal and cannot be assumed. Verify with the relevant MAC before billing Q5114 outside these three approved indications.

Maintaining clear documentation of the clinical indication in the patient record supports audit readiness, and compliance management software can help practices build structured audit trails for billing claims.

Billing and coding guidelines

Trastuzumab-dkst doses are not administered in neat 10 mg increments in clinical practice. Standard regimens range from 2 mg/kg to 8 mg/kg depending on the protocol.

Billing staff must calculate the number of units billed by dividing the total dose administered by 10, rounding to the nearest whole unit per payer policy. A 440 mg loading dose, for example, bills as 44 units of Q5114.

Common billing errors for Q5114 include miscalculating units (billing one unit for any dose regardless of size), missing infusion administration codes, and omitting the ICD-10 diagnosis code linking the claim to a covered indication.

Practices using claims management software can embed these documentation checkpoints directly into the claim submission workflow, reducing manual review time before each billing cycle.

ICD-10 diagnosis code crosswalk for Q5114

Every Q5114 claim requires a supporting ICD-10-CM diagnosis code that confirms medical necessity. The diagnosis must correspond to one of Ogivri’s FDA-approved indications.

Using an ICD-10 code that does not crosswalk to a covered indication is among the fastest routes to a claim denial. Verify current crosswalk codes against your HIPAA-compliant billing workflows and the applicable MAC LCD before submitting.

Important: ICD-10-CM requires the most specific subcode available. “C50.x” is a family code. Billers must select the subcode reflecting laterality (right/left/bilateral) and site. Submitting the unspecified family code alone when a specific subcode is available may trigger a claim edit. Always confirm crosswalk codes against the current CMS LCD for trastuzumab biosimilars, which can be found via the AAPC HCPCS code lookup.

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Medicare and Medicaid coverage for Q5114

Q5114 falls under Medicare Part B coverage as a physician-administered biologic. Part B covers drugs that cannot be self-administered and are given in a clinical setting. Trastuzumab-dkst, given by IV infusion, qualifies on both counts. Coverage is subject to medical necessity criteria matching an approved indication.

The same buy-and-bill mechanics apply to any physician-administered biologic, including the infusions IV therapy practices bill under their own HCPCS codes.

Medicare fee schedule and reimbursement methodology

Medicare reimburses Part B drugs under the Average Sales Price (ASP) methodology. For biosimilars including Q5114, reimbursement is typically set at ASP+6% of the reference product (Herceptin/J9355) or the biosimilar’s own ASP+6%, whichever applies under current CMS policy.

ASP rates update quarterly, so the rate that applied in Q1 of one year may differ by Q3. Never treat a static published rate as reliable without checking the current quarter’s ASP Drug Pricing file from the CMS fee schedule lookup. Practices that anchor budget forecasts to an outdated ASP figure routinely underestimate or overestimate drug margin.

Prior authorization requirements

Medicare does not uniformly require prior authorization for Q5114 across all MACs, but individual Medicare Advantage plans often do. Medicaid prior authorization requirements vary significantly by state.

The NC Medicaid program, for example, explicitly requires prior authorization for trastuzumab-dkst under Q5114. Commercial payers frequently require step therapy documentation showing prior treatment history before approving biosimilar coverage.

• Medicare (traditional/FFS): Prior auth generally not required, but MAC LCD criteria must be met. Document the HER2 testing result and staging in the clinical record.
• Medicare Advantage: Prior authorization typically required. Obtain before the first infusion cycle, not after.
• State Medicaid: Authorization requirements differ by state. Verify with the specific state’s Medicaid program or MAC before treatment begins.
• Commercial: Most commercial plans require prior auth for high-cost biologics. Check the payer’s individual drug policy for Ogivri specifically, not just trastuzumab generally, since biosimilar policies often differ from originator policies.

Practices that track prior authorization status alongside infusion scheduling can reduce the risk of administering a drug before payer approval is confirmed. Patient management workflows that link clinical scheduling to billing authorization status help prevent that mismatch in high-volume infusion settings.

Related biosimilar trastuzumab HCPCS codes

Multiple trastuzumab biosimilars have received FDA approval and separate HCPCS Q-code assignments. Each product has its own distinct code. Billing Q5114 for a product administered under a different biosimilar code is a false claims risk. Confirm the administered product matches the code before submission.

Note: Q-code assignments for biosimilars are subject to annual CMS review. Confirm current code status via the PGM HCPCS lookup tool or the CMS HCPCS Level II annual update files before the start of each plan year. A code that was active in a prior year may have been reassigned, retired, or merged. An EHR integration that pulls current HCPCS code data into an oncology or infusion practice’s system reduces the risk of using a stale code in claim submissions.

HER2-positive breast cancer billing: why accuracy matters

HER2-targeted therapies are among the highest-cost drug categories billed under Medicare Part B. A typical adjuvant trastuzumab-dkst course involves multiple infusion cycles over 12 months. Billing errors compound across a treatment course in a way they simply do not in lower-cost drug categories.

Three accuracy failures cause the majority of Q5114 claim problems in oncology practices:

• Wrong biosimilar code: Administering one trastuzumab biosimilar while billing the HCPCS code for another is a billing integrity failure. Each biosimilar (Ogivri, Ontruzant, Herzuma, Trazimera) carries its own distinct Q-code. The pharmacy dispensing record must match the code submitted.
• Incorrect unit calculation: Rounding up or down on unit counts without a documented dose-to-unit calculation creates overpayment or underpayment exposure. Document the calculation in the claim notes.
• Missing HER2 status documentation: Payers, particularly Medicare Advantage and commercial plans, routinely audit HER2-positive claims for pathology or molecular testing records confirming HER2 overexpression or amplification. Missing test documentation is a denial trigger even when the clinical indication is genuine.

Practices treating HER2-positive patients can reduce these risks by building structured documentation requirements into their clinical workflows. Digital intake forms that capture consent, HER2 testing results, treatment protocol, and cycle dates at the point of service create the audit trail needed to defend a biosimilar claim long after the infusion visit.

Pairing that with a practice management platform that integrates clinical documentation with billing submission keeps what’s documented and what’s coded aligned.

Revenue cycle management for high-cost biologics also requires close attention to contract terms. Oncology practices should verify whether their payer contracts reference the biosimilar’s own ASP or the originator’s ASP as the reimbursement basis, since the difference can be material over a full treatment course.

Regenerative medicine practices, which track their own biologic and PRP inventory just as closely, face similar contract-term scrutiny for any high-cost injectable. Clinical documentation workflows that flag ASP terms at the point of scheduling help practices avoid unwelcome reimbursement shortfalls at the end of a billing cycle.

Conclusion

Billing trastuzumab-dkst accurately requires more than knowing the code number. Unit calculations, ICD-10 specificity, prior authorization timelines, and quarterly ASP rate updates all affect whether a Q5114 claim pays cleanly or comes back as a denial. In oncology, where drug costs and treatment cycles are both high, small billing errors compound fast.

Practice management software like Pabau helps build these checkpoints into daily billing workflows, so documentation issues don’t turn into revenue loss. To see how it fits your practice’s billing process, book a demo.

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