The FCC Part 18 focuses on the EMC requirements for certain industrial, scientific, and medical digital equipment that is not included in Part 15. This standard regulates industrial, scientific, and medical equipment (ISM) that emits electromagnetic energy within the radio frequency spectrum to prevent harmful interference to authorized radio communication services. FCC 18 is a part of Title 47 of the Code of Federal Regulations.

The devices which fall under FCC Part 18 are the ones that are used for providing RF energy for other than telecommunications applications, such as heating, ionization of gases, mechanical vibrations, and acceleration of charged particles. A few such devices are fluorescent lighting, arc welders, microwave ovens, and medical machines.

The standard is divided into three subparts:

1. Subpart A: This subpart consists of scope, definitions, and general operating conditions. This subpart also includes the exemptions made for medical equipment. One such exemption is ultrasonic equipment and magnetic resonance equipment that is used for medical diagnostic and monitoring applications.
2. Subpart B: This subpart contains the procedures and requirements for authorization of introducing the equipment in the market and its applications. Subpart B also specifies the pre-requisites and format of the technical reports, important information to be shared with the user, and the declaration of the compliance information.
3. Subpart C: Technical standards: This subpart specifies the technical standards covered under FCC Part 18. They are:
   1. Operating frequencies.
   2. Prohibited frequency bands.
   3. Field strength limits.
   4. Conduction limits.
   5. The frequency range of measurements. 
   6. Methods of measurements.