On November 14, 2025, the White House released a Fact Sheet providing details on The Korea Strategic Trade and Investment deal first announced in July 2025. See Thompson Hine Update of November 17, 2025, for additional details. On December 3, 2025, the Office of the U.S. Trade Representative (USTR) issued a formal notice implementing certain tariff-related elements of this deal. The notice states that certain tariff modifications are necessary to implement the trade and investment deal. To do so, the Harmonized Tariff Schedule of the United States (HTSUS) has been amended to implement certain tariff elements, including: (i) the country-specific reciprocal tariffs; (ii) Section 232 tariffs on automobiles and automobile parts; (iii) Section 232 tariffs on timber, lumber, and their derivatives; and (iv) tariffs on certain aircraft and aircraft parts. In most instances, the tariff rate on most goods will be 15% or a “most-favored nation” tariff rate. An Annex to the USTR notice provides details as to the amendments to the HTSUS under Chapter 99.
The USTR notice is effective December 4, 2025. However, the modifications to the HTSUS as to automobiles and automobile parts entered for consumption or withdrawn from warehouse consumption are retroactively effective as of November 1, 2025. The modifications to the HTSUS as to goods subject to the country-specific reciprocal tariffs, timber, lumber, and their derivatives, and certain aircraft and aircraft parts, entered for consumption or withdrawn from warehouse for consumption are retroactively effective as of November 14, 2025.
A message posted to the CSMS system of U.S. Customs and Border Protection (CBP) provides detailed information and guidance for all related modifications to the additional rates of duty applicable to imported products from South Korea:
- Changes to Section 232 Duties on Automobiles and Automobile Parts
- Changes to Section 232 Duties on Wood Products
- Continued Exemption from Reciprocal Tariffs for Products Subject to Section 232
- Changes to Section 232 and Reciprocal Duties for Civil Aircraft
- Changes to Reciprocal Tariff
CBP notes that filers should take action to correct previously filed entries as necessary to reflect the modified duty rate under any applicable HTSUS headings. For unliquidated entries for which estimated duties have already been deposited, importers may file a post summary correction (PSC) to request a refund. Upon PSC approval, the refund will be issued at liquidation. For liquidated entries, importers may request a refund by filing a protest within 180 days after liquidation in accordance with 19 U.S.C. § 1514.