Monaghan first came to national attention in 2003 for his role as Winthrop Paroo opposite Kristin Chenoweth and Matthew Broderick in the ABC television adaptation of The Music Man.
In 2004, Monaghan began a recurring role as Chad, one of Dewey's special needs classmates on the Fox comedy series Malcolm in the Middle, which earned him the Young Artist Award as Best Young Television Actor in a Recurring Role [REF].