Brad Yacobian was a Starfleet officer in the 24th century. His planet of origin was Xendi Sabu II.
In 2369, as a lieutenant, he was a crew member aboard the USS Enterprise-D. He was one of seventeen individuals who were from worlds outside the Federation. His proteins were tested by Doctor Beverly Crusher for a possible configuration match with the fragments of a 4 billion-year old genetic program. The results came back negative. (TNG: "The Chase")
In 2371, he was a crewmember aboard the USS Voyager. He was among the crew stranded in the Delta Quadrant, when Voyager was forcefully brought there by the Caretaker.
In 2372, as a lieutenant commander, he was listed on the Planetary Geosciences Division duty roster. (VOY: "Parturition")
In 2374, he was listed on a crew manifest. (VOY: "The Killing Game", crew manifest)
The character was named for Unit Production Manager and Producer Brad Yacobian.