Code of Federal Regulations Title 5. Administrative Personnel § 5.575.308 Approval criteria and written determination

(1) The basis for determining that the unusually high or unique qualifications of the employee (or group of employees) or a special need of the agency for the employee's (or group of employees') services makes it essential to retain the employee(s);

(2) The basis for determining that the employee (or a significant number of employees in a group) would be likely to leave the Federal service in the absence of a retention incentive;  and

(3) The basis for establishing the amount and timing of the approved retention incentive payment and the length of the required service period.