HCPCS Level II code L3999 represents an upper limb orthosis, not otherwise specified, used to provide external support, stabilization, or correction for the arm or shoulder; the service typically involves fabrication or fitting of a custom or prefabricated orthotic device and the typical site of service is outpatient orthotics/prosthetics clinics, physician office-based orthotics services, or durable medical equipment suppliers.

For related coverage guidance, see recent payer policy updates: Prior Authorization for Durable Medical Equipment (DME), Continuous Passive Motion (CPM) Devices, Push-Rim Activated Power-Assist Device (E0986) — Manual Wheelchair Accessory.