A group art unit is a group of patent examiners at the U.S. Patent and Trademark Office working under the direction of a supervisory patent examiner. A four-digit number identifies the group, and each examiner within the group is responsible for determining the patentability of a specific subset of applications having a common inventive field.
For example, examiners working within group art unit 1760 examine patent applications in the field of organic chemistry, polymers, and compositions. On-the-other-hand, examiners working in group art unit 3790 examine patent applications involving medical instruments, diagnostic equipment, and treatment devices.