On 21 October 2004, she was a guest on the radio show Loveline. In January 2008, she appeared in Messiah V: The Rapture. In August 2008, Thomason was cast as a series regular in the CW show Easy Money. In late 2009, she appeared on General Hospital. After appearing in the pilot episode for White Collar as agent Diana Berrigan, she returned for the first-season finale. It was announced that she would appear on the series full-time in the second season. She is also the new voice of Diana in Hitman: Absolution.