The #1 hasn't been used in an INDYCAR sanctioned IZOD IndyCar Series race since the 2006 Indianapolis 500 when Michael Andretti ran the number earned from Dan Wheldon's 2005 championship, but hasn't been on-track on a full-time basis since Scott Dixon, the 2003 IZOD IndyCar Series Champion, used the number in 2004. The 2003, '04, '05, and '06, Champ Car Champions, Paul Tracy and Sebastien Bourdais, continued the tradition using the #1 until the 2008 merger with INDYCAR.
The team also announced that Marco Andretti will switch from the #26 to the #25 in 2013, while James Hinchcliffe will retain the #27.
During which USAC sanctioned the Indianapolis 500, after CART was established, the defending '500' champion had first rights to car #1 over the defending series champion, at Indy only. On several occasions the driver invoked the right including: Sneva (1984), Mears (1985), Sulivan (1986), Unser (1988), Mears (1989), and Luyendyk (1991).