Spinal interbody fusion cages and vertebral body replacement devices are sometimes disputed between 902139 (other artificial body parts) and 902110 (orthopedic appliances). Cochlear implants may be questioned against 9021900000 (hearing aids). The key is whether the device replaces a body part structurally or functionally — devices that restore a body structure are generally here, while those that merely support or correct function may fall elsewhere. CBP binding rulings are the most reliable reference for borderline products.

Both Ireland and Singapore host major manufacturing campuses for multinational medical device companies, meaning supply under this heading is often highly concentrated at the facility level even when sourced from multiple legal entities. A disruption at a single large-scale manufacturing site — whether from regulatory action, natural disaster, or logistics constraints — can have outsized impact on US supply. Importers of life-sustaining devices should assess single-site concentration risk and maintain safety stock or qualified alternate-site strategies.