Elrod was born into an American military family in Bitburg, Germany. After moving around the Philippines with his family, he was raised in Parker, Colorado. His father was an F-16 pilot and Elrod wanted to become a pilot himself. He earned his pilot license after graduation and became an air traffic controller.
After seeing the film Top Gun, Elrod decided to become an actor. He relocated to Los Angeles, in April 2004, to pursue a career in acting. Eventually, his performances in small parts in CSI: NY and Days of Our Lives brought him to the attention of the casting crew of Men in Trees, in which he played the part of Anne Heche's friend, occasional roommate, and sometimes love interest "Cash". In 2013, he starred in the films Home Run and Lone Survivor. In 2016 he play's Meredith new man in Grey's Anatomy. On August 1, 2016, he was cast as celebrity Travis Brenner in Chicago Fire.