Kirschbaum was a male Human who lived in the 24th century. In the 2360s and 2370s, he was an Admiral in Starfleet.

Prior to 2369, Kirschbaum had assigned Robert Young to Brundage Station as a punishment after Lieutenant Young told Kirschbaum, who he did not know was an Admiral, that nothing in Starfleet compared with snow skiing in Sun Valley. (TNG novel: The Soldiers of Fear)

In 2369, Admiral Kirschbaum was contacted by the Brundage Station crew to inform him that five Furies starships had appeared through a wormhole at Furies Point. Later, Admiral Kirschbaum ordered Jean-Luc Picard to take the USS Enterprise-D to Furies Point to negotiate with the Furies or engage them in battle. Admiral Kirschbaum also ordered the USS Madison, the USS Idaho and two other smaller ships to Furies Point and was hopeful of more assistant from other states, including the Klingons. (TNG novel: The Soldiers of Fear)

In 2371, Admiral Kirschbaum participated in a teleconference with Alynna Nechayev, Hajime Shoji, Judith Hayman, Benjamin Sisko and T'Kreng when an ancient version of the USS Defiant was found in Earth's oort cloud. Kirschbaum suggested that the Furies may have been responsible for sending the Defiant back in time and were responsible for the Bajoran wormhole's odd behavior, planning to use it invade the Alpha and Beta Quadrants again. (DS9 novel: Time's Enemy)