Simmons returned to the Indy Lights Series (formerly the Indy Pro Series) at the beginning of the 2008 season, driving for Team Moore Racing. He was given a chance to return to the IndyCar Series, albeit temporarily, to drive a second entry for A. J. Foyt Enterprises in the 2008 Indianapolis 500 and qualified 24th. He quickly moved up the field in the race until a pit lane incident damaged the car. A mechanical failure finally sent him into the wall during a caution period, resulting in a 28th-place finish.