HCPCS Level II code C1608 designates an implantable total dual-mobility prosthesis for the first carpometacarpal joint (the thumb base). It matters nationally as the aging population and demand for hand and thumb reconstructive procedures grow; a specific HCPCS Level II code supports consistent reporting, billing, and tracking of device utilization and payments across payers. Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn what the code represents clinically, the typical settings where the device is implanted, and what to expect in a national policy and billing context. The publication summarizes benchmarks and coverage trends where available, clarifies coding placement within the HCPCS Level II system, and provides clinical context for the prosthesis’ use in first carpometacarpal total joint replacement. Where payer-specific coverage policies and reimbursement benchmarks are available, they are summarized to aid billing compliance and claims preparation. Data not available in the input is noted explicitly where applicable.