Al-Ibaadiyyah is one of the deviant sects

Question: Is Al-Ibaadiyyah regarded as one of the deviant sects of Al-Khawaarij, and is it permissible to pray behind them?

Answer: Al-Ibadiyyah is one of the deviant sects because of their aggression and rebellion against Uthman ibnAffaan and `Alee (may Allaah be pleased with them both), and it is not permissible to pray behind them.… read more here.