Dever will play Misty, loyal best friend to Annika (Chloe Grace Moretz), who's often criticized for being outspoken and not thinking much about the future.
"Laggies" is the story of a woman (Keira Knightley) stuck in permanent adolescence who lies to her fiance in order to spend time with her teen friends.
The movie also stars Sam Rockwell.
Aside from starring on ABC's "Last Man Standing" and FX's "Justified," Dever's film credits include "Short Term 12," which won the SXSW Grand Jury Prize, and "The Spectacular Now."
She's also currently in talks to join "Grass Stains," a coming-of-age tale written and directed by Kyle Wilamowski.
"Laggies" is directed by Lynn Shelton — who also directed "Touchy Feely and "Humpday," as well as episodes of Fox's "New Girl," "Ben and Kate," and AMC's "Mad Men."
Written by Andrea Siegel, the Anonymous Content film started shooting in the Seattle area this week.
Dever is represented by United Talent Agency and Felker Toczek Gellman Suddleson.