The following time-in-grade restrictions must be met unless advancement is permitted by §300.603(b) of this part:

(a) Advancement to positions at GS-12 and above. Candidates for advancement to a position at GS-12 and above must have completed a minimum of 52 weeks in positions no more than one grade lower (or equivalent) than the position to be filled.

(b) Advancement to positions at GS-6 through GS-11. Candidates for advancement to a position at GS-6 through GS-11 must have completed a minimum of 52 weeks in positions:

(1) No more than two grades lower (or equivalent) when the position to be filled is in a line of work properly classified at 2-grade intervals; or

(2) No more than one grade lower (or equivalent) when the position to be filled is in a line of work properly classified at 1-grade intervals; or

(3) No more than one or two grades lower (or equivalent), as determined by the agency, when the position to be filled is in a line of work properly classified at 1-grade intervals but has a mixed interval promotion pattern.

(c) Advancement to positions up to GS-5. Candidates may be advanced without time restriction to positions up to GS-5 if the position to be filled is no more than two grades above the lowest grade the employee held within the preceding 52 weeks under his or her latest nontemporary competitive appointment.