The 21-year-old Briton will spend one day with the ART-run squad and the other with iSport, for whom he finished 11th in this year's championship and took his maiden series win at Monaco.
"I'm very happy to be back in a GP2 car at Jerez next week. I will be testing for Lotus and also iSport again," said Palmer.
"I'm looking forward to working with a new team and see how we work together and it will be good to have more time with iSport as well.
"Hopefully the weather will be dry and we can have some meaningful testing."
Johnny Cecotto Jr, who won twice with Addax on his way to ninth in this year's points, will meanwhile drive for Arden.