Since F2P launched we have seen many former members returning to STO and to 12th Fleet. The admiralty decided that any returning former member has to re-apply to the fleet.

However, if you were removed for inactivity and it has been less than a month since you were kicked from the fleet, then you may PM the Vice Admiral of your former division to request full reinstatement without having to re-apply. Such reinstatement in the first month after removal is up to the discretion of your VA.

the current division Vice Admirals are:
Engineering: Paragod513 (aka "Teklor")
Science: Mavar
Tactical: Kuvak