(1) Except as otherwise provided by this section, an employee of the Internal Revenue Service may be selected for a permanent appointment in the competitive service in the Internal Revenue Service through internal competitive promotion procedures if—
such term appointment or appointments were made under competitive procedures prescribed for permanent appointments;
the employee’s performance under such term appointment or appointments met established retention standards, or, if not covered by a performance management system established under section 9508, was rated at the fully successful level or higher (or equivalent thereof); and
Notwithstanding subchapter I of chapter 33, the Secretary of the Treasury may establish category rating systems for evaluating applicants for Internal Revenue Service positions in the competitive service under which qualified candidates are divided into two or more quality categories on the basis of relative degrees of merit, rather than assigned individual numerical ratings.
Within each quality category established under paragraph (1), preference eligibles shall be listed ahead of individuals who are not preference eligibles. For other than scientific and professional positions at or higher than GS–9 (or equivalent), preference eligibles who have a compensable service-connected disability of 10 percent or more, and who meet the minimum qualification standards, shall be listed in the highest quality category.
An appointing authority may select any applicant from the highest quality category or, if fewer than three candidates have been assigned to the highest quality category, from a merged category consisting of the highest and second highest quality categories.
Notwithstanding paragraph (4), the appointing authority may not pass over a preference eligible in the same or higher category from which selection is made unless the requirements of section 3317(b) or 3318(c), as applicable, are satisfied.
The Secretary of the Treasury may detail employees among the offices of the Internal Revenue Service without regard to the 120-day limitation in section 3341(b).
Notwithstanding any other provision of law, the Secretary of the Treasury may establish a probationary period under section 3321 of up to 3 years for Internal Revenue Service positions if the Secretary of the Treasury determines that the nature of the work is such that a shorter period is insufficient to demonstrate complete proficiency in the position.
(e) Nothing in this section exempts the Secretary of the Treasury from—
any obligation under a court order or decree relating to the employment practices of the Internal Revenue Service or the Department of the Treasury.