C9146 Mirvetuximab Soravtansine HCPCS Reimbursement | OpenPayer

Summary & Overview

HCPCS C9146: Mirvetuximab Soravtansine-Gynx Injection, 1 mg

HCPCS Level II code C9146 denotes the injection of mirvetuximab soravtansine-gynx, 1 mg, an oncology-directed antibody–drug conjugate. As a drug-specific HCPCS Level II code, C9146 facilitates billing for administered doses in outpatient infusion settings and hospital outpatient departments and matters nationally because it standardizes reporting for a high-cost, specialty oncology medication used in targeted cancer therapy.

Key payers considered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of coverage considerations and payer presence, as well as benchmarking context where available. The publication outlines clinical context for use of mirvetuximab soravtansine-gynx, typical sites of administration, and common billing elements associated with injectable oncology therapies.

This article summarizes what the code represents, the service setting, and payers commonly involved in reimbursement. It highlights areas readers can expect to learn about: national coverage patterns, billing and coding considerations tied to specialty cancer drug administration, and where to look for further payer-specific policy details. Data not available in the input is noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareC9146HCPCS Level IImirvetuximab soravtansineoncologyinfusion therapyinjectable drugdrug administrationspecialty pharmacy

Billing Code Overview

HCPCS Level II code C9146 represents injection of mirvetuximab soravtansine-gynx, 1 mg. This code is used to report administration of the specified antibody-drug conjugate for oncology treatment. The service type is injectable oncology therapy, and the typical site of service is an outpatient infusion center or hospital outpatient department.

Data not available in the input.

Clinical & Coding Specifications

Clinical Context

A 62-year-old female with recurrent, platinum-resistant epithelial ovarian cancer is referred to a medical oncology infusion clinic for targeted antibody-drug conjugate therapy. The oncology team prescribes mirvetuximab soravtansine-gynx dosed per body weight and prepares a single-use vial-based product billed as HCPCS Level II code C9146 representing 1 mg of the agent. The patient arrives at the outpatient oncology infusion center for pre-infusion assessment, including vital signs, laboratory review (complete blood count, hepatic and renal function), and confirmation of eligibility criteria (e.g., folate receptor alpha expression if required by the therapeutic indication). A registered nurse performs IV access placement, administers pre-medications as ordered (antiemetics, antihistamines or corticosteroids when indicated), and monitors for infusion-related reactions during and after administration. The pharmacy compounds the dose under sterile conditions, verifies the exact milligram amount, and documents lot number and expiration for billing and safety. Post-infusion monitoring occurs for the recommended observation period with documentation of any adverse events. The billing department submits the drug administration charge using C9146 units reflecting the milligrams administered, with applicable modifier codes appended for unusual circumstances (for example, QK/QX for pharmacist services, or 52 for reduced services) consistent with payer policies.

Coding Specifications

Modifier

HCPCS C9142: Injection, bevacizumab-maly (Alymsys), 10 mg

HCPCS-C9743-BULKING-SPACER-MATERIAL-INJECTION-IMPLANTATION

HCPCS C9743: Injection/Implantation of Bulking or Spacer Material

HCPCS-C8932-MRA-SPINAL-CANAL-WITHOUT-CONTRAST

HCPCS C8932: Magnetic Resonance Angiography, Spinal Canal Without Contrast

HCPCS-C9604-CORONARY-GRAFT-REVASCULARIZATION-SINGLE-VESSEL

HCPCS C9604: Percutaneous Coronary Graft Revascularization, Single Vessel

HCPCS-C9056-GIVOSIRAN-INJECTION-0-5-MG

HCPCS Level II C9056: Injection, givosiran, 0.5 mg

HCPCS-C1784-OCULAR-DEVICE-INTRAOPERATIVE-DETACHED-RETINA

HCPCS C1784: Ocular Device, Intraoperative, Detached Retina

HCPCS-C9755-PERCUTANEOUS-MAGNETIC-GUIDED-AV-FISTULA-CREATION-RF

HCPCS C9755: Percutaneous Magnetic-Guided Arteriovenous Fistula Creation

HCPCS-C2624-IMPLANTABLE-WIRELESS-PULMONARY-ARTERY-PRESSURE-SENSOR

HCPCS C2624: Implantable Wireless Pulmonary Artery Pressure Sensor

HCPCS-C9767-LOWER-EXTREMITY-REVASCULARIZATION-LITHOTRIPSY-STENT-ATHERECTOMY

HCPCS C9767: Lower Extremity Revascularization with Lithotripsy, Stent, Atherectomy

HCPCS-C9607-CTO-PERCUTANEOUS-REVASCULARIZATION-SINGLE-VESSEL

HCPCS C9607: CTO Percutaneous Coronary Revascularization, Single Vessel

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Taxonomy Code	Specialty	Notes
`207Q00000X`	Medical Oncology	Primary specialty prescribing and overseeing `mirvetuximab soravtansine-gynx` therapy
`363LP0800X`	Hematology-Oncology	Hematology-oncology specialists involved in systemic therapy management
`3336S0300X`	Infusion Therapy	Registered nurses and infusion specialists administering IV biologic therapies
`1835S0105X`	Clinical Pharmacy	Oncology pharmacists responsible for compounding, dosing verification, and medication safety
`363A00000X`	Internal Medicine (Oncologic care)	Hospital-based internists or hospitalists coordinating inpatient infusions or complications

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`C56.9`	Malignant neoplasm of ovary, unspecified	Primary ovarian malignancies are the typical indication for `mirvetuximab soravtansine-gynx` in folate receptor–positive epithelial ovarian cancer
`C57.9`	Malignant neoplasm of other and unspecified female genital organs	Used when primary site is other female genital organ with similar therapeutic indications
`C79.6`	Secondary malignant neoplasm of intra-abdominal lymph nodes	Represents metastatic spread that may be present in patients receiving systemic targeted therapy
`Z85.3`	Personal history of malignant neoplasm of breast	Relevant when prior malignancy impacts therapy selection or eligibility for trials
`Z08`	Encounter for follow-up examination after completed treatment for malignant neoplasm	Used for surveillance visits related to prior cancer treatment and ongoing therapy monitoring

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`96413`	Chemotherapy administration, intravenous infusion technique; up to 1 hour, single or initial drug	Used when administering a single initial IV infusion of a chemotherapeutic or biologic agent in an outpatient setting for up to one hour
`96415`	Chemotherapy administration, intravenous infusion technique; each additional hour	Billed for each additional hour of infusion time beyond the first hour when infusion duration exceeds 1 hour
`96365`	Intravenous infusion, therapeutic, prophylactic, diagnostic; initial, up to 1 hour	Used when a non-chemotherapy therapeutic biologic is administered and payer policy accepts this code for monoclonal or antibody-drug conjugates when appropriate
`96417`	Chemotherapy administration for multiple non-overlapping IV drugs, each additional hour	Used when complex infusion regimens require multiple-hour administrations in oncology infusion settings
`36415`	Collection of venous blood by venipuncture	Performed prior to infusion for labs used to assess eligibility and monitor toxicity
`95165`	Professional services for allergen immunotherapy not directly applicable	Included only if allergy testing or desensitization procedures are performed in the same encounter (rare)

Note: If a CPT code is not applicable in a specific payer’s policy for billing targeted antibody-drug conjugates, facility-specific drug administration codes or payer-specific guidelines may apply.

`22`	Increased procedural services	When the service requires substantially greater work than typical (rare for standard drug infusion; may apply if extraordinary preparation/documentation required)
`23`	Unusual anesthesia	When general anesthesia is required for an associated procedure (rare for outpatient infusion)
`52`	Reduced services	When a reduced dose or truncated service is provided relative to standard (e.g., partial vial not administered)
`53`	Discontinued procedure	When the infusion is started but halted due to patient reaction or adverse event
`54`	Surgical care only	Not typically applicable to drug billing; include only when concurrent surgical services billed separately
`55`	Post-operative management only	Not typically applicable; relevant if postoperative care billed separate from infusion
`56`	Pre-operative management only	Not typically applicable to infusion services
`62`	Two surgeons	Not applicable to infusion itself; used when two surgeons are involved in a procedure associated with drug administration
`78`	Return to OR for related procedure following initial surgery	Not applicable to routine infusion; used if surgical re-intervention occurs
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery	Not applicable to infusion billing
`CO`	Staged or related procedure or service by another physician	Use when another clinician performs a related service in the global period
`CQ`	Modifiers for pharmacist—pharmacist provided services	When a pharmacist provides clinically significant services billable under payor-specific programs
`QK`	Medical direction of two, three, or four qualified individuals by a physician or other qualified health care professional	When physician medically directs qualifying personnel during drug administration per payer rules
`QX`	Qualified nonphysician anesthetist with medical direction by a physician	Rare for infusion; included when medical direction applies under anesthesia rules

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