The United States National Time Trial Championships are held annually to decide the American champions in this cycling discipline, across various age and gender categories. Originally, in 1975, the time trial event distance was 25 miles. It later changed to 40 km, and still later changed to the current distance of 32.3 kilometers.

David Zabriskie is a retired professional road bicycle racer from the United States, who competed as a professional between 1999 and 2013. His main strength is individual time trials and his career highlights include stage wins in all three Grand Tour stage races and winning the US National Time Trial Championship seven times. Zabriskie is known for his quirky nature, including singing before stages and the interviews he does with fellow riders in the professional peloton which are posted on his web site.