After competing in the 2003 Indianapolis 500, Andretti retired from full-time IndyCar racing. He led the race for 28 of the opening 94 laps before a throttle linkage failure put him out of contention once again. That year he bought into the "Team Green" squad run by brothers Kim and Barry Green in CART. It became Andretti Green Racing and for 2003, the team moved to the Indy Racing League IndyCar Series.