"Alabama" entered the Bremerton Annex of Naval Base Kitsap at Bangor in 2005 to undergo a nuclear reactor refueling overhaul and conversion of her ballistic missile systems to support the Trident II D5 ballistic missiles, which replaced her Trident I C4 ballistic missiles and launchers; "Alabama" was the last Trident C4-equipped submarine to be refitted with the Trident D5 missile system.