Additon attended Western High School in Davie, Florida, and was selected by the San Francisco Giants in the 42nd round of the 2004 Major League Baseball Draft.[2] He opted to play baseball at Lynn University, then continued his playing career with the Kalamazoo Kings of the Frontier League for the 2008 season.[3][4] Additon was hired as a professional baseball umpire in 2010 and started in the Gulf Coast League. By the 2016 season, Additon had been promoted to the Triple-A level.[4][5] He began working as a call-up umpire during the 2017 Major League Baseball season, making his debut on May 21, 2017, working at first base during a game Target Field.[6] As a call-up umpire, Additon was behind home plate when Corey Kluber pitched a no-hitter on May 19, 2021.[7][8] He was promoted to the full-time MLB staff on February 4, 2022.[7]