2006: Marco joined his father's Andretti Green Racing IndyCar Series team for 2006. His first Indy 500 saw him narrowly miss a historic victory. A crash by Felipe Giaffone instigated a caution period on lap 191. Marco's father Michael took the lead on lap 194 under caution when cars ahead of him made pit stops. At this stage, Marco was immediately behind his father in second place. One lap after returning to green-flag racing, Marco put a passing move on his father and took the lead, seemingly on the way to victory. However Sam Hornish, Jr., recovering from a penalty earlier in the race, was closing quickly.