Coleman was discovered at an indoor karting center in Houston, TX by LeMans champion Price Cobb. He set a record at 16 years-old at the Rolex 24 at Daytona when he and his teammates finished 7th in the GT class driving a Porsche 911 GT3, making them the youngest team in history to drive and complete the famed race.
Following extensive training and racing in stock cars and formula cars, he made his big league stock car racing debut in the ARCA RE/MAX series at Nashville Superspeedway on April 15, 2006, where he finished second. In 9 starts, Coleman posted 8 top five finishes including 3 poles and 1 win. On June 10 of the same year, Coleman made his debut in the Busch Series the same week he graduated from high school.In 2007, Coleman ran 17 races for Joe Gibbs Racing in the #18 Carino’s Italian Grill Chevrolet in the NASCAR Busch Series with Aric Almirola, Kevin Conway, and Tony Stewart filling in the remainder. He put together 3 top 5 finishes, 5 top 10 finishes, 7 top 15 finished and 9 top 20 finishes in only 14 races, including back to back top 5 finishes at Milwaukee and Kentucky and another top 5 finish at Watkins Glen.
It was announced on October 2007 that Coleman would leave Joe Gibbs Racing after the 2007 season. He signed with Baker Curb to drive the #27 Kleenex Ford Fusion full-time in the NASCAR Nationwide Series in 2008, and it was later announced that he had signed with Hall of Fame Racing as well, with plans of running a part-time schedule in 2008, and a full-time run in 2009. He made his Sprint Cup Series debut in the #96 Texas Instruments DLP HDTV Toyota Camry starting at the 3M Performance 400 on August 17th, 2008, due to previous driver J.J. Yeley being released. Due to his new Sprint Cup ride, Coleman left Baker Curb Racing. However, after only one start, he was released by Hall of Fame Racing. In 2009 Coleman returned to the Nationwide Series for Joe Gibbs Racing. He shared the #20 Toyota with Joey Logano and Denny Hamlin and drove 8 races. In 2010 he will move back to Joe Gibbs Racings #18 Toyota, the car he drove in 2007 and share the ride with Kyle Busch.