McFadzean began his career as a playwright in Chicago, later earning a master's degree in theater at Illinois State University.
[2] While attending the University of Evansville in Indiana, where he earned a bachelor's degree in theater, it was there he met Matt Williams.
McFadzean would be the first person that Williams hired for the writing staff of the first season of the sitcom Roseanne.
They went on to create and produce Carol & Company, Thunder Alley, Buddies, Soul Man and their most successful creation, the sitcom Home Improvement starring Tim Allen.
McFadzean currently lives outside Los Angeles in La Cañada Flintridge with his wife Elizabeth.