Television:
* "The Suite Life of Zack & Cody" (2005-2008) as Arwin Hawker
* "The Suite Life on Deck" (2008-2011) as Arwin Hawker
* "Pair of Kings" (2010-2013) as King Angus
* "Jessie" (2011-2015) as Tony
* "The Middle" (2009-2018) as Mike Heck (recurring role)
* "The Thundermans" (2013-2018) as Dr. Colossal
* "Nicky, Ricky, Dicky & Dawn" (2014-2018) as Mr. Sheffield (recurring role)
* "Fuller House" (2016-2020) as Arwin Hawker
* "The Goldbergs" (2013-present) as Dave Kim (recurring role)
* "The Adventures of Kid Danger" (2014-2020) as Captain Man (voice)
* "Henry Danger" (2014-2020) as Captain Man (voice)
* "The Big Show Show" (2020-present) as Brian (himself)
Film:
* "The Suite Life Movie" (2008) as Arwin Hawker
* "The Dog Who Saved Christmas" (2009) as Mr. T
* "The Dog Who Saved Christmas Vacation" (2010) as Mr. T
* "The Dog Who Saved Christmas: The Littlest Angel" (2012) as Mr. T
* "The Search for Santa Paws" (2010) as Mr. T
* "Santa Paws 2: The Santa Pups" (2011) as Mr. T
* "Spooky Buddies" (2011) as Mr. T
* "The Dog Who Saved Easter" (2014) as Mr. T
* "The Dog Who Saved the Holidays" (2016) as Mr. T
* "The Christmas Chronicles" (2018) as Elf
This is not an exhaustive list, but it covers many of his most notable and popular roles. Stepanek has also done voice acting in numerous animated projects. He has also written and directed several projects.