Mark Webber will have a new engineer for the 2013 Formula 1 season, with Ciaron Pilbeam being replaced by Simon Rennie.
Pilbeam is set to become chief race engineer at Lotus.
Rennie moves in the opposite direction, having worked with Lotus driver Kimi Raikkonen last season.
A Red Bull statement said: "We can confirm that Ciaron Pilbeam has left the team to take up a new position with Lotus.
"We're pleased to welcome Simon Rennie to Red Bull Racing who will be Mark Webber's race engineer."