HTS Heading 3903

Polymers of styrene, in primary forms

All 6 HTS codes under heading 3903 (polymers of styrene, in primary forms), with their duty rates from the 2026 HTS Revision 23. General duty 6.5%.

Every line of heading 3903

  • 3903 Polymers of styrene, in primary forms.
  • 3903.11.00.00 Expandable (under: Polystyrene) (kg): General 6.5%; Special Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 15.4¢/kg + 46%.
  • 3903.19.00.00 Other (under: Polystyrene) (kg): General 6.5%; Special Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 15.4¢/kg + 46%.
  • 3903.20.00.00 Styrene-acrylonitrile (SAN) copolymers (kg): General 6.5%; Special Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 15.4¢/kg + 45.5%.
  • 3903.30.00.00 Acrylonitrile-butadiene-styrene (ABS) copolymers (kg): General 6.5%; Special Free (A,AU,BH,CL,D,E,IL,J,JO,KR,MA,OM,P,PE,S,SG); Column 2 15.4¢/kg + 47%.
  • 3903.90 Other (under: Polymers of styrene, in primary forms).
  • 3903.90.10.00 Methyl methacrylate-butadiene-styrene (MBS) copolymers (kg): General 6.5%; Special Free (A,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 15.4¢/kg + 67.5%.
  • 3903.90.50.00 Other (under: Other) (kg): General 6.5%; Special Free (A*,AU,BH,CL,CO,D,E,IL,JO,KR,MA,OM,P,PA,PE,S,SG); Column 2 15.4¢/kg + 46%.

From MFG Calcs data: Plastics in primary forms

U.S. imports of plastics in primary forms (headings 3901, 3902, 3903, 3904, 3906, 3907, 3908) came to $12.49B in 2025, with $674M in calculated duty: an effective duty of 5.4%, every duty included.

Effective duty in Sep 2026: 7.6%, against 7.5% in Sep 2025.

Largest sources in 2025: Canada $4.15B at 0.3% effective duty; South Korea $1.51B at 5.1% effective duty; Mexico $1.17B at 0.3% effective duty; Germany $921M at 8.4% effective duty; Japan $863M at 7.9% effective duty.

These are family totals from U.S. import statistics published through USITC DataWeb, not this heading's rate alone; effective duty is calculated duty as a share of customs value, an estimate, not a ruling.

About these rates

The rates are those printed in the 2026 HTS Revision 23, published by the U.S. International Trade Commission. A 10-digit statistical line takes the rates printed on the 8-digit line above it. Chapter 99 duties (Section 232, Section 301, IEEPA) depend on the product, the origin and the date, are charged on top, and are not included. A code here is a strong lead, not a ruling: confirm it with a customs broker or a CBP binding ruling.

Last reviewed 2026-11-12.