Section XVIII · Optical, photographic, measuring, medical or surgical instruments

9027.81

Mass spectrometers

How this code is built
90

Chapter

Optical, photographic, measuring, medical or surgical instruments

27

Heading

The product family within the chapter

81

Subheading

The specific good, identical worldwide

The first six digits are the same in every country that uses the Harmonized System. The United States adds two more for the tariff rate and, often, two more for statistics — which is why the rates below are listed against 8- and 10-digit numbers rather than against this code.

How the schedule reaches this code

  1. 90Optical, photographic, measuring, medical or surgical instruments
  2. 9027Instruments and apparatus for physical or chemical analysis (for example, polarimeters, refractometers, spectrometers, gas or smoke analysis apparatus); instruments and apparatus for measuring or checking viscosity, porosity, expansion, surface tension or the like; instruments and apparatus for measuring or checking quantities of heat, sound or light (including exposure meters); microtomes; parts and accessories thereof:
  3. Other instruments and apparatus:
  4. Mass spectrometers

Published US duty rates

Duty is set at the 8- or 10-digit line, not at this 6-digit subheading, so more than one rate can sit under this code.

  • 9027.81.00.00Mass spectrometersNo.
    General
    Free
    Special (FTA)
    —

    No preferential rate published.

    Column 2
    40%

    Countries without normal trade relations.

Schedule footnotes

  • See 9903.88.01.

A reference to Chapter 99 means an additional action — a Section 232 or 301 measure, an exclusion, or a quota — applies on top of the rate above.

This is the listed rate. Antidumping and countervailing duty orders, Chapter 99 actions and preference qualification all change what is actually collected, and classification is a judgement about your goods. Verify with your licensed customs broker before you file.

Other subheadings in heading 9027

Source: U.S. International Trade Commission (USITC) — 2026 HTS Revision 12, released 2026-07-21, published at hts.usitc.gov. A U.S. Government work in the public domain.