CPT code 0402T describes corneal collagen crosslinking using riboflavin (vitamin B2) eyedrops activated by ultraviolet light to strengthen corneal fibers. This outpatient ophthalmic procedure, sometimes performed with epithelial removal and pachymetry to confirm corneal thickness, is an increasingly relevant treatment for progressive corneal ectatic disorders such as keratoconus. Nationally, the code matters for coverage policy, access to sight-preserving interventions, and setting appropriate reimbursement for ambulatory ophthalmology services. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare.

Readers will learn clinical context for the procedure, typical sites of service, and the policy and coverage landscape across major national payers. The publication summarizes benchmarks where available, highlights recent policy updates affecting utilization and prior authorization, and outlines billing considerations that influence facility and professional payments. When specific data elements are not provided in the source, the text indicates "Data not available in the input." The goal is to equip ophthalmology providers, billing specialists, and policy analysts with a concise briefing on CPT code 0402T, its clinical use, and the payer context that shapes adoption and reimbursement nationally.