Section 315.904 - Basic requirement(a) An employee is required to serve a probationary period prescribed by the agency upon initial appointment to a supervisory and/or managerial position.(b) An employee is required to complete a single probationary period in a supervisory position and a single probationary period in a managerial position, regardless of the number of agencies, occupations, or positions in which the employee serves. However, an agency may by regulation provide for exceptions to the probationary period for managers who have satisfactorily completed a probationary period for supervisors when justified on the basis of performance and experience.(c) Employees who, as of the date this requirement is effective, are serving or have served in Federal civilian supervisory or managerial positions without time limitation, or in time-limited supervisory or managerial positions under an official assignment exceeding 120 days, are exempt from its provisions, except that supervisors who are assigned to managerial positions may, according to agency regulations, be required to serve a probationary period for managers.