29 C.F.R. § 1620.15 : Labor — REGULATIONS RELATING TO LABOR — EQUAL EMPLOYMENT OPPORTUNITY COMMISSION — THE EQUAL PAY ACT — Jobs requiring equal skill in performance

(a) In general. The jobs to which the equal pay standard is applicable are jobs requiring equal skill in their performance. Where the amount or degree of skill required to perform one job is substantially greater than that required to perform another job, the equal pay standard cannot apply even though the jobs may be equal in all other respects. Skill includes consideration of such factors as experience, training, education, and ability. It must be measured in terms of the performance requirements of the job. If an employee must have essentially the same skill in order to perform either of two jobs, the jobs will qualify under the EPA as jobs the performance of which requires equal skill, even though the employee in one of the jobs may not exercise the required skill as frequently or during as much of his or her working time as the employee in the other job. Possession of a skill not needed to meet the requirements of the job cannot be considered in making a determination regarding equality of skill. The efficiency of the employee's performance in the job is not in itself an appropriate factor to consider in evaluating skill.
(b) Comparing skill requirements of jobs. As a simple illustration of the principle of equal skill, suppose that a man and a woman have jobs classified as administrative assistants. Both jobs require them to spend two-thirds of their working time facilitating and supervising support-staff duties, and the remaining one-third of their time in diversified tasks, not necessarily the same. Since there is no difference in the skills required for the vast majority of their work, whether or not these jobs require equal skill in performance will depend upon the nature of the work performed during the latter period to meet the requirements of the jobs.

29 C.F.R. § 1620.15