The Harmonized Tariff Schedule of the United States (HTSUS) is the official document that governs the classification and duty rates for all goods imported into the United States. Here's everything you need to know about where it comes from, how it's structured, and how to use it.
What Is the USITC?
The U.S. International Trade Commission (USITC) is an independent, nonpartisan federal agency that provides trade expertise to both the legislative and executive branches of the U.S. government. One of its core responsibilities is publishing and maintaining the Harmonized Tariff Schedule of the United States.
The USITC does not set tariff rates — that is the role of Congress and the President. The USITC's job is to accurately publish and update the schedule as laws and trade agreements change.
How Often Is the HTS Updated?
The HTS is updated multiple times per year through numbered revisions. The current version used on LookupHTS is 2026 Revision 5. Updates are triggered by:
- New or modified trade agreements (FTAs)
- Congressional legislation
- Presidential proclamations adjusting duty rates
- International HS system updates (every 5–6 years from the WCO)
- Technical corrections and reclassifications
How Is the Schedule Structured?
The HTSUS is organized into 21 sections (broad groupings like "Animal & Vegetable Products" or "Machinery & Mechanical Appliances") and 98 chapters. Within each chapter, products are arranged from broad headings to increasingly specific subheadings.
The schedule also includes:
- Section and Chapter Notes: Legal text that governs what belongs in each section (these take precedence over general descriptions)
- General Notes: Rules that apply across the entire schedule, including country-specific programs
- General Rules of Interpretation: Six rules governing how to classify goods
- Additional U.S. Notes: Country-specific additions beyond the international HS
Where Can I Access the Official Schedule?
The official USITC HTS schedule is available at hts.usitc.gov. It's a comprehensive reference but can be difficult to navigate for beginners. LookupHTS makes the same data searchable in plain English with additional features like the duty calculator and FTA country display.
Understanding Section and Chapter Notes
One of the most overlooked aspects of the HTS is the legal notes that appear at the beginning of each section and chapter. These notes are not supplementary information — they are legally binding text that controls how products within that section or chapter are classified. A product that seems to fit a particular heading based on its description may actually be excluded by a chapter note directing it elsewhere.
For example, Chapter 39 covers plastics and articles thereof, but its chapter notes specify that it does not cover certain products like textile fabrics impregnated with plastics (which go to Section XI, Textiles) or footwear with plastic soles and textile uppers (which go to Chapter 64, Footwear). Ignoring these notes is one of the most common classification errors and can result in using the wrong HTS code, the wrong duty rate, and potential penalties from CBP.
Chapter 98 and Chapter 99: Special Provisions
Chapter 98 covers special classification provisions — goods that qualify for duty-free treatment based on how they are used rather than what they are. This includes returned American goods, goods imported for repair, temporary imports under bond, and personal effects of returning U.S. residents. Understanding Chapter 98 provisions can save importers significant duty when the circumstances apply.
Chapter 99 is used for temporary modifications to the tariff schedule. This is where you will find Section 301 tariffs on Chinese goods, Section 232 tariffs on steel and aluminum, and other Presidential proclamation-based tariff adjustments. Chapter 99 codes are applied in addition to the regular HTS classification — your product gets its base duty rate from its regular HTS code (Chapters 1–97) and any additional tariff from the applicable Chapter 99 subheading. These codes are frequently created, modified, and removed, making Chapter 99 one of the most dynamic parts of the schedule.
How to Stay Current With HTS Changes
Because the HTS is a living document that changes multiple times per year, importers need a reliable process for staying current. The USITC publishes each new revision on its website along with a summary of changes from the prior revision. Subscribing to trade compliance newsletters, working with a customs broker who monitors tariff changes, and using tools like LookupHTS that reflect the latest revision data are all effective strategies. For products subject to volatile trade policy — particularly those affected by Section 301, Section 232, or new executive orders — monitoring changes is not just good practice but essential for accurate cost planning and compliance.