NAICS codes describe the manufacturing industry, while HTS codes govern import classification and duty assessment. When importing rolling stock, the relevant HTS heading (typically Chapter 86) determines applicable duties and any trade remedy exposure; the NAICS code is used for statistical and regulatory reporting purposes rather than tariff determination.

Certain steel and aluminum components used in rolling stock may be subject to Section 232 tariffs on those base materials. Additionally, specific rolling stock products sourced from particular countries could be subject to antidumping or countervailing duty orders. Importers should conduct a thorough HTS-level review and consult a licensed customs broker to assess current exposure.