The US will impose a 100 percent tariff on patented drugs and related ingredients not produced domestically or not covered by government pricing agreements, according to a revised pharmaceutical import policy announced this week. Korea-origin goods face a differentiated 15 percent rate under the new framework—a reflection of existing bilateral trade agreements that compliance systems must now account for separately.

This two-tier structure introduces classification complexity that goes beyond standard HTS rate lookups. The 85-percentage-point spread between the default rate and the Korea-specific rate means country-of-origin validation is now a high-stakes data integrity issue for any system processing pharmaceutical imports.

Exemption pathway: Companies that sign a Most Favored Nation (MFN) pricing agreement with the US Department of Health and Human Services (HHS) and establish local US production facilities may qualify for tariff exemptions. This creates a third rate tier—zero—that depends on entity-level compliance status rather than product classification alone.

The policy applies specifically to patented drugs and their active pharmaceutical ingredients (APIs). Both finished drugs and active ingredients must be produced domestically to qualify for the exemption, meaning origin determination now requires supply chain visibility into drug substance manufacturing locations, not just final product assembly.

Korean biosimilar manufacturer Celltrion confirmed Monday that its US portfolio will be largely shielded from tariff exposure under the new rules. The company's infliximab subcutaneous formulation, Zymfentra, qualifies for exemption because its drug substance is manufactured at Celltrion's Branchburg, New Jersey facility. The company plans to expand that plant's capacity from 66,000 liters to 141,000 liters—a 75,000-liter addition—to position itself for increased contract manufacturing demand.

Data architecture impact: Rate determination for pharmaceutical HTS codes now requires a minimum of three conditional checks: (1) country of origin, (2) domestic production status for both finished product and API, and (3) HHS MFN pricing agreement enrollment. Systems caching flat rates by HTS code will return incorrect duty calculations.

For compliance engineering teams, the immediate technical problem is that pharmaceutical tariff rates are no longer static values tied to HTS classifications. The Korea exception means origin-based rate branching is mandatory. The HHS agreement exemption means importer-specific flags must override baseline rates. And the dual domestic-production requirement—covering both drug substance and finished product—means a single import may require origin verification at multiple supply chain stages.

Trade compliance systems serving pharmaceutical importers should audit rate logic for HTS chapters covering medicaments (primarily Chapter 30) and organic chemicals used as APIs (Chapter 29). Any hardcoded rates or simple country-rate mappings will produce calculation errors under the new framework.

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