Season 4 will consist of 32 episodes and the Lab Rats newest sister, Elena, is now a character.
Tyrel Jackson Williams as Leo Dooley
Billy Unger as Chase Davenport
Kelli Berglund as Bree Davenport
Spencer Boldman as Adam Davenport
Trevor Jackson as Trevor Davenport
G. Hannelius as Elena Davenport
TBA as Dill Davenport