CPT code 61737 designates laser interstitial thermal therapy (LITT) for multiple brain lesions or for one or more complex lesions that require multiple trajectories. LITT is a minimally invasive, image-guided neurosurgical technique that uses laser energy to ablate intracranial lesion tissue and is increasingly used for select metastatic tumors, radiation necrosis, and other focal brain pathologies. Nationally, recognition of this code matters because it defines billing and reporting for a specialized procedure with distinct resource use, imaging needs, and facility requirements.

Key payers in this overview include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The discussion highlights how payers approach coverage and reimbursement for LITT, operational considerations for site of service, and common billing modifiers used with complex neurosurgical procedures.

Readers will find a concise clinical context for CPT code 61737, typical settings where the service is delivered, and the elements that affect billing and utilization. The publication provides benchmarks and policy-relevant context where available, clarifies common billing practices, and notes when input data are not provided. This summary is intended for billing professionals, surgical program managers, and policy analysts seeking a national-level briefing on the code and its clinical use.