HCPCS Level II code J3358 denotes ustekinumab supplied for intravenous injection, billed per 1 mg. As a high-cost biologic used in autoimmune and inflammatory conditions, accurate coding for the drug itself is central to claim adjudication, reimbursement, and utilization tracking across outpatient infusion settings. Nationally, coding clarity for biologic agents like ustekinumab affects payer coverage determinations, prior authorization workflows, and provider billing practices.

Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how J3358 is used in clinical practice, typical sites of service for administration, and the common commercial and federal payers involved in coverage decisions. The publication summarizes available national benchmarks, common billing modifiers (listed separately), and relevant policy considerations that influence claim processing for intravenous biologics.

This resource is intended to help coding and billing staff, revenue cycle managers, and policy analysts understand the clinical and administrative context of J3358, including where to look for payer-specific policies and what aspects of documentation and coding typically drive coverage and payment outcomes.