Summary & Overview
HCPCS Level II J1304: Injection, tofersen, 1 mg
HCPCS Level II code J1304 denotes a per-milligram billing unit for tofersen, an injectable specialty medication used in neurology. The code is used when billing the pharmaceutical product itself and is relevant for facilities and clinicians that provide specialty drug administration in outpatient infusion centers, hospital outpatient departments, and physician offices. Nationally, accurate coding for high-cost specialty injectables like tofersen matters for payer coverage determinations, prior authorization workflows, and claims adjudication.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of code definition and clinical context, descriptions of typical sites of service, and guidance on which stakeholders commonly engage with this code. The publication outlines typical billing considerations for a specialty injectable product unit code, summarizes common modifier usage provided in the input, and indicates where input data is missing.
This resource is intended to inform revenue cycle professionals, pharmacy and therapeutics staff, and clinicians involved in specialty drug delivery about the billing identity of tofersen at a national level, and what to expect when preparing claims and interacting with major payers.
Billing Code Overview
HCPCS Level II code J1304 represents Injection, tofersen, 1 mg. This code is used to bill for administration or provision of the medication tofersen in a per-milligram unit of measure. The service type is pharmaceutical product administration/infusion tied to a specialty neurology drug. The typical site of service is outpatient infusion clinic or specialty ambulatory setting, including hospital outpatient departments, infusion centers, and physician offices that administer specialty injectable therapies.
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is an adult diagnosed with a pathogenic or likely pathogenic SOD1 mutation–associated amyotrophic lateral sclerosis (ALS) who receives J1304 (injection, tofersen, 1 mg) as part of disease‑modifying therapy. The clinical workflow begins with neuromuscular specialist evaluation (neurologist) confirming genetic testing results and assessing eligibility. Baseline assessments include neurologic exam, pulmonary function testing (FVC), serum laboratory studies (including liver function tests), and counseling on risks/benefits. Tofersen is administered as an intrathecal or intravenous infusion per prescribing information and site protocols; typical site of service is an outpatient infusion center or hospital outpatient department. During each treatment visit the infusion nurse or pharmacist verifies dose based on mg units billed with J1304, prepares the drug, performs infusion and monitors for infusion reactions and adverse events; follow‑up includes periodic labs and functional assessments documented in the outpatient medical record. Common payer interactions include prior authorization and specialty pharmacy coordination with payors such as Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier — standard service |