updated 04/20/2011 AT 5:30 PM ET
•originally published 04/22/2011 AT 10:45 AM ET
Mary McCormack is adding to her troop.
The actress, who stars as a WITSEC Marshall in USA Networks’ In Plain Sight, is expecting her third child with producer Michael Morris, her rep confirms to PEOPLE exclusively.
McCormack’s pregnancy is being written into the show’s storyline. “The upside of being knocked up along with my character – no need for stunt boobs,” McCormack says.
McCormack, 42, and Morris were married in 2003. Their new baby will join daughters, Margaret, 6½, and Rose, 3½, at home in Albuquerque, N.M., where the series shoots.
The fourth season of In Plain Sight will premiere on May 1.