Covered employee means a person, including an applicant or transferee, who performs or will perform a safety-sensitive function for an entity subject to this part. A volunteer is a covered employee if:
(1) The volunteer is required to hold a commercial driver's license to operate the vehicle; or
(2) The volunteer performs a safety-sensitive function for an entity subject to this part and receives remuneration in excess of his or her actual expenses incurred while engaged in the volunteer activity.
49 CFR § 655.4
For this part, the terms listed in this section have the following definitions. The definitions of additional terms used in this part but not listed in this section can be found in 49 CFR Part 40.