5 CFR §315.905
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
The authority to determine the length of the probationary period is delegated to the head of each agency, provided that it be of reasonable fixed duration, appropriate to the position, and uniformly applied. An agency may establish different probationary periods for different occupations or a single one for all agency employees.