The writer told SFX that the show's lead characters will all have different abilities following the events of last year's Christmas special.
"They're all going to have brand new powers," he confirmed. "Nobody will have the same powers as in the second series."
Overman added that making such a significant change to the show's format is "quite daunting".
"They've had their powers for two series, and you've got to come up with a whole new set of powers," he said. "We're very much constrained with the type of powers we can do because you have to think about what works in terms of the character and story, as well as what's achievable on our budget."
He also admitted that the five regular characters will wear their orange jumpsuits in the next run, despite having finished their community service.
"That's the look of the show," he suggested. "They're on community service and their jumpsuits are their de facto superhero costumes, so I will be finding a way to get them back in the jumpsuits fairly quickly."
Misfits will return to E4 in the autumn.
> Click here for our complete coverage of Misfits