From 2004 to 2006, Pietz starred as Jennifer Aspen's crazy sister in the ABC sitcom Rodney. During 2007-08 season, she played the mother in The CW sitcom Aliens in America. She also had guest starring roles on Ally McBeal, CSI: Crime Scene Investigation, The Division, Law & Order: Special Victims Unit, Burn Notice, The Closer, Curb Your Enthusiasm, Nip/Tuck, Desperate Housewives, Two and a Half Men, and How to Get Away with Murder. She also had a recurring role as Donna in the NBC comedy series The Office in 2010.