5 C.F.R. § 3.2
Subject to receipt of satisfactory evidence of the qualifications of the person to be appointed, OPM may authorize an appointment in the competitive service without competitive examination whenever it finds that the duties or compensation of the position are such, or that qualified persons are so rare, that, in the interest of good civil-service administration, the position cannot be filled through open competitive examination. Any person heretofore or hereafter appointed under this section shall acquire a competitive status upon completion of at least one year of satisfactory service and compliance with such requirements as OPM may prescribe. Detailed statements of the reasons for the noncompetitive appointments made under this section shall be published in OPM's annual reports.
5 C.F.R. § 3.2