Once you get passed over you have to wait your time to qualify again. That means whatever held you back you have to fix before being eligible again. Once eligible you have to write a letter to the powers that be to get back on the list. But if the list is expired then so might your opportunity. At least thats the way I understand it be. Contact your GS Administrator. They are the ones who pulls the files and sign off on your promotion along with the AGM & GM of the depot. Good luck.