CPT code 66720 represents cryotherapy of the ciliary body to lower intraocular pressure by reducing aqueous humor production. This ophthalmic procedure is clinically important as a treatment option for refractory glaucoma and other conditions where lowering intraocular pressure is necessary to preserve vision. Nationally, its use affects surgical ophthalmology practice patterns, payer coverage decisions, and outpatient surgical case mix. Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the code’s clinical intent and typical sites of service, plus what to expect in the full publication: national benchmarks for utilization and reimbursement, payer coverage considerations, relevant clinical context for appropriate use, and common billing modifiers and service-line implications. The publication also outlines documentation elements typically associated with this procedure and highlights areas where policy updates or coding clarifications are often needed. Data not available in the input is noted where applicable.