If a court order acceptable for processing awards a former spouse a lump-sum amount from the employee annuity and does not state the monthly rate at which OPM should pay the lump-sum, OPM will pay the former spouse equal monthly installments at 50 percent of the gross annuity (subject to the limitations under §838.211) at the time of retirement or the date of the order, whichever comes later, until the lump-sum amount is paid.