When a within-grade increase has been withheld, an agency may, at any time thereafter, prepare a new rating of record for the employee and grant the within-grade increase when it determines that he or she has demonstrated sustained performance at an acceptable level of competence. However, the agency shall determine whether the employee's performance is at an acceptable level of competence after no more than 52 calendar weeks following the original eligibility date for the within-grade increase and, for as long as the within-grade increase continues to be denied, determinations will be made after no longer than each 52 calendar weeks.
5 C.F.R. §531.411