5 U.S. Code § 9814 - Qualifications pay
(a) Notwithstanding section 5334, the Administrator may set the pay of an employee paid under the General Schedule at any step within the pay range for the grade of the position, if such employee—
(b) If an exercise of the authority under this section relates to a current employee selected for another position within the Administration, a determination shall be made that the employee’s contribution in the new position will exceed that in the former position, before setting pay under this section.
(c) Pay as set under this section is basic pay for such purposes as pay set under section 5334.
(d) If the employee serves for at least 1 year in the position for which the pay determination under this section was made, or a successor position, the pay earned under such position may be used in succeeding actions to set pay under chapter 53.
(e) Before setting any employee’s pay under this section, the Administrator shall submit a plan to the Office of Personnel Management and the appropriate committees of Congress, that includes—
(4) the relationship between the exercise of authority under this section and the use of other pay incentives; and