According to the US Navy, the newest Expeditionary Sea Base ship officially joined the fleet on May 8, 2021, at Naval Air Station North Island, the USS Miguel Keith (ESB-5). The ship was named in honor of Lance Corporal Miguel Keith, United States Marine Corps. Miguel Keith was originally a non-commissioned ship, with a USNS prefix but, like her sister ships, she was commissioned by the Navy, in order to provide combatant commanders greater operational flexibility in utilizing the ESBs in accordance with the laws of armed conflict.