Country of origin for pharmaceuticals is generally determined by where the last substantial transformation occurred — typically the country where the API is formulated into its final dosage form. However, this analysis is fact-specific and should be confirmed with a licensed customs broker or trade attorney, as it affects both duty rates and any applicable trade remedy exposure.

Certain pharmaceutical inputs and finished products originating from countries subject to Section 301 actions may carry additional duties depending on their specific HTS classification. Importers should review current Section 301 product lists against their tariff lines, as exclusions and modifications have been issued for some pharmaceutical categories.