In 2012, McDorman played the male lead role opposite Laura Prepon in the short-lived NBC sitcom Are You There, Chelsea?. He later joined the cast of Showtime comedy-drama, Shameless as Mike Pratt. He starred in the film See You in Valhalla opposite Sarah Hyland, and in 2014 co-starred in Clint Eastwood's film American Sniper. Also in 2014, McDorman was cast in the male lead role opposite actress Analeigh Tipton in the ABC romantic comedy series, Manhattan Love Story. In 2015, he starred in CBS's Limitless as Brian Finch, a young man who uses a mysterious drug called "NZT" to enhance his intelligence to help the FBI solve cases. The TV series continued the story of the motion picture of the same name. The show was cancelled after one season.