Heading 99039903.91.04
Effective with respect to entries on or after January 1, 2025, and before January 1, 2026, articles the product of China, as provided for in subdivision (e) of U.S. note 31 to this subchapter
The U.S. notes it refers to
As the 2026 HTS Revision 22 writes them (official notes); each code opens its page. Whether this heading applies to goods depends on the origin, the date and the product: the calculator says it.
U.S. note 31(e)
(e) Heading 9903.91.04 applies to facemasks of textiles, disposable, of China, described in statistical reporting number 6307.90.9870, effective with respect to goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern standard time on January 1, 2025, and before January 1, 2026.