(a) OPM shall be responsible for:

(i) Open competitive examinations for admission to the competitive service that will fairly test the relative capacity and fitness of the persons examined for the position to be filled.

(ii) Standards with respect to citizenship, age, education, training and experience, physical and mental fitness, and for residence or other requirements that applicants must meet to be admitted to or rated in examinations.

(iii) Standards of suitability based on character and conduct for appointment to a position in the competitive service, for appointment to a position in the excepted service where the incumbent can be noncompetitively converted to the competitive service, and for career appointment to a position in the Senior Executive Service.

(iv) Minimum standards of fitness based on character and conduct for appointment in any other position in the excepted service of the executive branch, except for (A) positions in any element of the intelligence community as defined in the National Security Act of 1947, as amended, to the extent they are not otherwise subject to OPM appointing authorities, and (B) positions where OPM is statutorily precluded from prescribing such standards.”

(b) In addition to the names of persons who qualify in competitive examinations, the names of persons who have lost eligibility on a career or career-conditional register because of service in the armed forces, and the names of persons who lost opportunity for certification or who have served under career or career-conditional appointment when OPM determines that they should be given certification, may also be entered at such places on appropriate registers and under such conditions as OPM may prescribe.

(c) Whenever the Office of Personnel Management (1) is unable to certify a sufficient number of names to permit the appointing officer to consider three eligibles for appointment to a fourth-class postmaster position in accordance with the regular procedure, or (2) finds that a particular rate of compensation for fourth-class postmaster positions is too low to warrant regular competitive examinations for such positions, it may authorize appointment to any such position or positions in accordance with such procedure as may be prescribed by OPM. Persons appointed under this paragraph may acquire competitive status subject to satisfactory completion of a probationary period prescribed by OPM.

(a) OPM shall establish and administer a career-conditional appointment system for positions subject to competitive examinations which will permit adjustment of the career service to necessary fluctuations in Federal employment, and provide an equitable and orderly system for stabilizing the Federal work force. A competitive status shall be acquired by a career-conditional appointee upon satisfactory completion of a probationary period, but the appointee shall have career-conditional tenure for a period of service to be prescribed by regulation of OPM. When an employee has completed the required period of service his appointment shall be converted to a career appointment without time limitation: Provided, That his career-conditional appointment shall not be converted to a career appointment if the limitation on the number of permanent employees in the Federal civil service established under paragraph (b) of this section would be exceeded thereby. Persons selected from competitive civil service registers for other than temporary appointment shall be given career-conditional appointments: Provided, That career appointments shall be given to the following classes of eligibles:

(1) Persons whose appointments are required by statute to be made on a permanent basis;

(2) Employees serving under career appointments at the time of selection from such registers;

(3) Former employees who have eligibility for career appointments upon reinstatement; and

(4) To the extent permitted by law, persons appointed to positions in the field service of the U.S. Postal Service for which salary rates are fixed by the act of July 6, 1945, 59 Stat. 435, as heretofore or hereafter amended and supplemented.

(b) Under the career-conditional appointment system there shall be a limit on the number of permanent employees in the Federal civil service which shall be the ceiling established by section 1310 of the Supplemental Appropriation Act, 1952 (65 Stat. 757), as amended. In the event section 1310, supra, is repealed, OPM is authorized to fix such limitation on the number of permanent employees in the Federal civil service as it finds necessary to meet the needs of the service.

(c) OPM may determine the types, duration, and conditions of indefinite and temporary appointments, and may prescribe the method for replacing persons holding such appointments.

Subject to such modifications as OPM finds to be necessary in the interest of good administration, appointments to positions in agencies' headquarters offices which are located within the metropolitan area of Washington, DC, shall be made so as to maintain the apportionment of appointments among the several States, Territories, and the District of Columbia upon the basis of population.

Persons selected from registers of eligibles for career or career-conditional appointment and employees promoted, transferred, or otherwise assigned, for the first time, to supervisory or managerial positions shall be required to serve a probationary period under terms and conditions prescribed by the Office.