He wrote the films Scoob!, The Addams Family, The Christmas Chronicles and its sequel, and Free Guy.
Lieberman started his writing career in the Walt Disney Feature Writer's Program and has written on several projects in development including Short Circuit, Monopoly, Zombie Brother and Mr. Toad's Wild Ride.
[7] Lieberman's spec script, Free Guy, was bought by 20th Century Fox and landed on the 2016 Black List.
Paramount Pictures preemptively acquired Yumanzu, a high concept family adventure pitch.
[10] Warner Bros. acquired Meebo and Me, an original comedic family adventure spec script by Lieberman.