Lazier began to compete in the newly formed Indy Racing League in 1996. Lazier won the Indianapolis 500 that season, and he became one of the most dominant drivers in the series for a period of time, winning eight races overall and the series championship in 2000. Lazier began to drive only at the Indianapolis 500 in 2007 and continued to enter the Indianapolis 500 through 2009. He did not return to the series until 2013 at the Indianapolis 500 when he competed for Lazier Partners Racing, a team started by his father Bob Lazier and various investors. Lazier and the team repeated their efforts in 2014, 2015, 2016 and, for the final time, in 2017.